Stephen, nice experiment and revised theory, but here's another thought. Your body heat overwhelmed the freezer capacity to cool its contents and heat rises, so the bottom was frozen and the top hot, and the slightly open door added to the effort. I've written a few articles on walk-in freezers and coolers for restaurant use. These freezers and coolers can pull down the temperature on a 5 gallon (~22 liter) pot of soup to safe storage temps in a couple of hours. But those items are a passive temperature and not the active temperature a mammal uses. The main problem your experiment presented was a warm body in a small, artificially frozen space. Your freezer was running overtime to cool your body, so the motor and coolant ran hotter in the area above the floor that mostly remained cold. Healthy, fed, live animals expend a prodigious amount of heat, especially humans. As for losing hear through the sides, that's absolutely a good possibility if the sides are not insulated. But this was a good experiment and it points out the difficulties of cooling food products for safe storage as much as trading gear for outdoors enthusiasts keeping survivably warm in cold conditions. Thanks for giving this a trial run.
There is another variable to consider, and that's humidity. When you're outside in freezing temperatures the humidity is effectively zero, and unless you close yourself inside of a tent you'll have pretty low humidity throughout the night. But that's not how the freezer would work; your breath and evaporation from the heat of the body would thaw the water with nowhere to escape, creating a humid environment in which temperature will transfer much faster, not to mention the perceived temperature would be much lower. And I think that would be an issue even with an industrial freezer, unless it's obscenely large for such a test. Alternatively Steven could just take a trip to some place that has snow at this time of year and test there. It'd be expensive, but less than building or renting a huge freezer, and he'd get to experience actual real world conditions too.
Great points. And I feel @amunak_ also raised a valid point about humidity. Last winter I camped on a beach in Washington in January. It was only +30F / -1C, but because the air was saturated with salt water, I could barely keep warm wearing all of my layers. No joke, I was warmer at -25F / -30C than I was in humid +30F / -1C with identical gear and layering. I'm lucky, and happy, I decided to bring extra insulation. I only did so because I was worried about getting wet (always happens on the coast), not because of water content in the air.
Just for reference an average human with a dayly caloric need of 100kcal emits ~100w (~350btu) of heat, double if you are larger/heavyer and are reasonably trained. That can easily overwhelm chest freezers since they are often highly insulated in combination with a small heatpump to be as energy efficiant as possible. He was definitly burning up because the frezzer couldn't handle his boddy heat.
@@JustMikeHI found out the same when stationed in the southeast while in the army. It was just crazy that a resident of Maine who was regularly outside and active in temps well below 0F would be shivering while wearing every piece of gear he had at 35F, but the difference was
Also I suspect insulation. Those chest freezers have crazy amounts of insulation, so don't let the heat (or cold) escape that well, as well as someone pointed out above humiditiy. So I suspect that's why Stephen was really hot, and then was feeling cold of the pad because of the contrast of the two. May sound odd to say that a tent is better, but the evaporation would, whereas you would get a sort of heatbox effect in a freezer.
I saw the thumbnail and thought you might have spend the night in a walk-in freezer like a restaurant would have. Maybe you can fin a closed restaurant that you can contact the owners of to get permission and try it that way?
One issue with the ASTM rating system is the plates they apply are perfectly flat, when human bodies aren't. Your hip bones, butt, shoulders stick out more than the flat of your back, calfs, etc. This would give an un-even compression of the pad, and I suspect for most multi-layer designs, more compression = less loft = less insulation.
You separated the freezer into two micro climates by adding an insulated layer (the sleeping pad) midway through the space. The lower climate is pre-cooled (full of ice), any heat is being drawn away on three sides, and it's insulated from above. The upper climate contains an organic heater (you), and is being fed by warm air from the surrounding room (open lid). This dramatic temperature differential between the two environments neatly demonstrates how effective the pad's insulation is.
Hi. I’m a theoretical physicist and have been modelling sleeping bags and sleeping pads, taking into account conduction, convection and heat radiation. Your experiment was really impressive and not a waste of time. The big issue is that the testing methods don’t take into account the fact that the body compresses certain areas of the pad more than others. In the majority of cases the body is warmer than the ground and so convection inside the pad shouldn't occur. Heat must rise from warmer lower temperatures to higher cooler temperatures, in order to convect. However, when the body depresses the pad, it produces a warm section under the body and the edges of the pad are actually higher and colder. Heat then convects from the base of the warm sleeper to the higher and cooler outsides. Modelling suggest that these side convection currents can be suppressed by having the long longitudinal chambers in the pad, as in most Expeds, and not short transverse chambers as in most Thermarests. I note that the Nemo Tensor has short transverse chambers. It’s a serious design flaw that doesn’t reveal itself in the tests.
Tell Nemo if they’re so confident in their products to sponsor a video with enough money that you can purchase a walk in freezer. You can become the sleep pad test guy.
good video. Some science experiments may fail but also reveal a weakness as you did with the potential of cold air infiltrating the side walls. I agree that really, the only way to test these things is to just go camping and use it as you would in the field. Real life, real answers. Lot's of variables, but you should be able to get a general feel for how it performs.
Justin found the same thing with new Tensor on glacier in Canada. Side cooling is a thing, whether irl or in freezer. Very likely an advantage for quilts that drape over the sides of pad. Or for Zen-bivy, who 'sheet' their pad. Meanwhile, pad-maker's are finally learning to suspend reflective layers, they have not yet solved the cold edge problem. ...they will. Perhaps, they will provide 'Trekology-style' tabs along the sides? Or pre-'sheet' the pad-edge? An internal vertical reflective layer or two just inside the edge is another possible approach?
I really appreciate your commitment and *inside* the *icebox* thinking! You've definitely given us a lot to think about when it comes to cold weather sleeping pads. Makes me want to finally pull the trigger on a winter hammock/under-quilt setup.
I appreciate you also took the time to show an experiment that did not go as expected. Some may think it was a failure, but showing what happened and why it didn't work as expected was very educational. THANK YOU for showing that. Goodhart's Law: “When a measure becomes a target, it ceases to be a good measure.” This is always the case once marketing has a number they can point to to say their product is better than competition. It does not matter if that number does not reflect the practicality of that measurement in a real world scenerio. Even when a company understands quality and practicality is what keeps existing customers, sometimes the goal of quality is lost to achieve that measurement as a target. Seeing how Nemo stands up to this challenge will be interesting. At the very least it will show us what direction they intend to go as a company.
I agree designing for numbers isn’t good but this is better than what we had before where every brand just made up numbers based on whatever test they made up themselves. At least this way we have SOME consistency.
If you want to try this again i wouls suggest looking at refrigerated trailer rental. Locally it would cost me 500 dollars for the minimum 3 day rental on a 6 by 10 trailer deaigned as a temporary fridge/freezer for restaurants.
Haven't seen this mentioned. Both freezers and refrigerators have heating elements. The rubber seals need good contacts to be air tight and thus are heated to melt ice that might form and yield a poor seal. It's a bit pedantic but it's important to state that cold doesn't travel, heat does. Either in the form of radiation or conduction. Essentially these pads are baffled Ballons with space blankets inside. This system reflects heat back toward the sleeping surface and creates air gaps to reduce conduction through the pad. I think you're correct to seen the walls as a problem, active cooling on the sides. Normal condition inside a tent will mean rather stagnant air and so I'd expect comparatively minor heat loss to the cold air. Kind of like the difference in an air fryer to a conventional oven. The temperatures may be the same but the flowing air creates constant heat at the surface. Whereas conventional ovens see pockets of relatively cool air that surround the surface of whatever you're cooking. Onto the localized coldness outside the chest: I wonder if the mattress conforming to your body causes contact between the reflective layers. I suspect that reducing the effective layers from 4 to 3 would cause a significant loss in local R value.
The idea that the pad may be conforming to my body and causing reflective layers to touch is an interesting hypothesis. And something the machine with flat plates couldn’t test.
Holy crap dude a freezer that's the size and shape of a coffin is where you're trying to sleep?!?!? This shows your commitment to your channel. Keep up the great work! Please be careful. 💛
Hopefully it's not disappointing like the ether light xt extreme. The r value was better than the xtherm but I slept cold when the weather was in the positives. Maybe this rating system needs to be revamped because as of now the xtherms feels like the only way to go. Thanks for testing these pads out. I watch every video of yours
I feel the same way. I want the Xtherm to be dethroned but I’d be lying to say I’m not skeptical. I’m meeting with Nemo’s director of quality next week to talk about their testing and hopefully find some (better) ways I can do some testing myself. We will see. I’m honored! I’d love to connect sometime.
I'm almost certain I know why you had the issues you did, and weirdly, a better/easier/more accurate way to test. I can see why you wanted to close the lid, but really what that did was to create an area where your exhalation warmed the space above you; since there wasn't much air circulation, you just wound up heating that space, and since a freezer is designed to insulate, well, you actually kept that space warm (insulation, with few exceptions, cares whether you're insulating to keep heat out or cold in). So error number one was closing the door. Yes, I realize this means you'll generally get 'garage temp' above you, but... Consider what you're really testing is the thermal transfer between the pad and your body. While the atmosphere above you might be warmer and skew your comfort overall, you'll absolutely be able to tell if there's a good thermal barrier between you and the ice. If you wanted a more accurate full-on winter condition, you could rig some ducting under the ice, put a fan in the freezer, and pull the air gently through the ducting so that it's very cold, then shut the lid with a gap that is roughly the area of the ducting. That'll keep cold air circulating above you to better simulate the temperature. As for the sides, while I take your point, the truth is that if it is freezing so is the air on the sides of the pad. I'm not sure I think that should be omitted as in real world conditions you'd have exposed/cold sides. IMO the EXPED 7R (and others in that same series) are superior that they use down. There's certainly some oddities with that, and special care has to be taken about storage and use, but it does work incredibly well.
This, to me, highlights the importance of shelter choice in cold weather. If you use a shelter where the fly doesn’t contact the floor on all sides, has a mesh only inner, or, worst of all, is too large of an internal volume for the occupant(s), you lose the benefits of a warmer microclimate within your tent, increasing the potential for this kind of issue being a reality. I spent 4 nights between -8°c and -16°C last winter, with two nights being in 15inches of snow, and I was perfectly fine with my x-lite because I snow packed my 3.5 season tent and managed air-flow sensibly. At those temps, condensation freezes to your fly and you just don’t need to worry about moisture internally if you layer down with a synthetic or primarily use synthetics. During said trip, the inside of my tent was roughly 8-10°c warmer inside vs out and I slept like a baby, even on a pad not technically suitable. You don’t always need the highest quality gear but you always need the highest quality information.
A+ for the effort, but as you found out it's not easy to crate real world test. I don't know what the problem is but a freezer have active cooling system that will suck out heat in a completely different way than when sleeping on the ground or snow. Actually, snow is a fairly good insulator so while it's cold to start with it wont lead the heat away. Same goes for ground while even when you slept on only the ice blocks you slept on something that has a both fairly high heat transfer coefficient and (while lower than water) also has a high specific heat capacity meaning that it can suck up a lot of body heat compared to ground/sand or snow. You seem to know quite a few people in the industry so maybe you could get some hints from one of them on how to get your test more representative. In the freezer or on ice blocks. Also, I think that your comments about the cold sides of the freezer are correct. They will transfer heat much better than the air you'll usually have on the sides of the mat.
Yeah, also if the freezer is detecting a warm item, or warm air coming in (wasn't a airtight seal obviously), it might be running on overdrive trying to bring the system down to temperature.
@@MyLifeOutdoors Your conclusion about cold coming from the sides is also why I place a foam pad on top of (instead of below) the air mattress in the winter.
Hi Steven, thank you for the effort to undertake the freezer test. I think you have correctly identified the failing in the R value measuring system. Exped make a pad that is filled with down, the Synmat, and therefore may not suffer heat transference from the side. Is there any chance you could experiment with a mat that uses a different structure to insulate, like the Synmat? (Apologies in advance for another poor nights sleep). Thanks again for your work to address this issue.
All in the name of science! I have used the xlite down to 5C with no problems but below it gets a little chilly. To boost performance I tried wrapping in a space blanket to avoid heat exchange at the sides and have been comfortable down to -5C. Yes the 70g space blanket brings the xlite into xtherm territory but I don't have one. 😔
little off topic but man... nothing better than a nice warm night of sleep in the freezing cold. I love the smell of the air and the cold on my face then rolling over in the warm sleeping bag putting my face into the pillow. ahhh so nice hahaha.
I use an Invoker pad. It's heavy at 5lb. But under $100 rated a R9. It has a memory foam core so it needs to be rolled and strapped to the outside of the bag. But the extra weight is worth it to keep you alive and comfortable. It's also self inflating. Why you get ultra light for the rest of your gear.
Perfect timing! Just listened to you and Justin on the Backpacking Podcast talking about this. Then boom! Here’s the video! Sorry it didn’t work out, but as others have said, you’ve (we) learned a lot. Thanks Steve!
I used to work for REI and was able to see how they use a similar freezer with a sensor covered mannequin to do similar tests. BUT 2 differences. They were testing sleeping bags, not pads. At the time the thermarest pro lite plus pad was the standard used to test sleeping bags. Also, the mannequin doesn’t exhale warm air! Which I think was part of your problem.
Not a waste of money. Now you can store sides of beef. Also, cold does not "go" anywhere. Cold is just the absence of heat energy. Meaning, the heat in your body was going down into the pad and out the sides, most of it probably above the first baffle, being in direct contact with a solid object that was being continually cooled down. But the cold was staying exactly where it was.
This is a really neat experiment, even if it didn't go quite as planned! As you have found, freezers like this can achieve very low temperatures but are not built with the expectation of a lot of active heat generation (I believe a human body is about 40W of heat when resting) happening inside the compartment and so struggle to keep up, and since the cooling coils snake through the walls it can generate a pretty unrealistic temperature profile throughout the body of the freezer. If you can't track down a walk-in freezer or freezer warehouse nearby, I don't know if you have to give up on your chest freezer idea quite so quickly. Freezers like this are highly insulated boxes so they'll dramatically slow air exchange with the outside, which works in your favour to maintain a temperature differential with the outside. The freezer's own cooling is not actually that important here, so you should actually just turn the freezer off and use it as an insulated box. Rely instead only on the ice as your source of cooling; at least from the video, your ice was still mostly intact after the tests which means you have enough heat capacity there for an overnight test without the ice melting and letting the temperatures rise. In terms of your temperature differential problem, the issue is air circulation. There's not much spare space around and with the open edge at the top, you have a massive difference in the bottom and top temperatures with no good way to equalize those. Adding a fan or two inside the freezer to drive air down to the cold space below you and equalize the air throughout the freezer would probably do a lot to ensure the below-pad and above-pad temperatures are much closer. For the ventilation/suffocation aspect, look into Heat Recovery Ventilators. These are used in high-efficiency home design to exchange fresh air with the outside without losing all the heat/cold from inside the space, and you could drill a couple big holes in the lid of your freezer and install one of them with some ducting and fans to keep the air inside the freezer fresh/breathable while dramatically reducing the heat loss. You could then keep the freezer lid totally closed while still getting fresh (but pre-cooled) air, which would help massively with keeping the temperature inside the freezer well controlled. Additional note: If you really need even more cooling power (I doubt it, with the above changes) then you could rig up a window AC unit to blow cold air in as well as they're much higher output than a freezer's normal compressor. This is a bit tricky though because it is hard to mount and direct the air in and you'd need to replace the controller with an aftermarket one to convince the AC to keep running at very low temperatures.
I spent 4 nights in -15°C in army issue gear and only lost feeling in both my big toes for 9 months. But it was fun! Like the frozen fleece masks in the mornings.
This does explain a lot, I felt something similar with my Big Agnes sleep system. I used the insulated q core with the pad the slides into the bottom of the sleeping bag. I try to counter-act with alpaca wool poncho wrapping around or sometimes inside.
Freeze the ice as you did, than take the plastic containers out of the freezer, and place a layer of wood on top of the plastic containers containing the ice. Than you stay there for an hour, measuring the temperature above and below the pad, which you obviously place above the wood slab. You do this with every pad to see how they perform.
That freezer was like one tight ass igloo (not Igloo as in the brand name coolers.). Your own breath also contributed to the warming effect in the dead air space inside the box, just like Inuit shelters do in the great white north. Real world conditions would have allowed for the heat build-up in your tent to dissipate through the walls of the shelter, reducing the temperature rapidly, allowing for more realistic interaction between your sleeping pad and your body. So, closing the lid on your “coffin” really skewed the results, as much as sleeping on hard frozen ice versus warmer, insulating snow did.
I’m new to your channel and just wanted to drop by to say a big THANK YOU for really testing out gear, going way out of your way to find their true performance and for shedding light on less known and less conventional gear/equipment. I have thoroughly enjoyed your videos like tents set up on top of your car and this one sleeping in a coffin sized freezer LMAO 😂 These beat any Netflix movie. Binge watching over the holidays!
Chest freezers are dope and super efficient. Put a bunch of food in it and you'll always have something good to eat and won't have to go grocery shopping as often.
I was in a tent that was ripped apart by the wind in driving rain, hail and sleet. We awaited out the night with no sleeping bag and just our hiking gear on our sleeping mats. Mine was a Sea To Summit and I never felt the cold through the mat, only from the air. Could you suggest the best value, lightweight, storm tent? The winds were above 120km/hr and temps down to 0°C
Technology Connections has a good video that may explain why your freezer acted that way. It's likely part of the frost free design and should cycle over to cooling given enough time.
So if you are really committed to this project, you could build a slightly larger cold room with a couple layers of 4" foam and use the freezer's guts to cool it. All you'd need to do is vent the condenser side of the circuit out of the "room". But this all requires that the compressor can handle more heat than your body puts out, otherwise you will overrun the thing.
I have spent a night in a large freezer-room, to test gear for an expedition in the Arctic. Usually I can handle -20 C with ease, but in this case, I struggled. Probably because of the moisture building up in the room, creeping into my sleeping bag, even when using a vapour barrier liner. Breathing was uncomfortable as well..
Pretty cool way to try something out. A large walk-in freezer would be better suited for your experiment, but I think lawyers and liabilities would keep business owners from letting you try out gear in there. I've spent the night at -17F up in Michigan's UP. Not only can it get really cold, but the humidity also affects the perception of cold. I know Alaska gets freaky cold, but it's also extremely dry. Come out to the UP! Extreme conditions gear testing, tons of beautiful winter hiking and skiing, all wrapped up in one great location.
I believe that you are correct in your assessments. What I found that worked very well was to have a torso length piece of the blue closed cell foam pad on top of the air pad. It was the only way the air pad was warm enough. At the time I assume that was because of the poor performance of the sides of the air pad. For reference I had the original Big Agnes Insulated air pad and the temperature was 25 degrees all night. I used a synthetic quilt with just under 2 inches of loft.
It may or may not have contributed to this experiment, but the side-to-side movement of air absolutely contributes to a colder feeling pad. This is exacerbated with movement. Some pads do a better job than others at isolating and deadening this internal air movement. This is a blind spot in the ASTM testing method.
Did you want the freezer to keep other items frozen or were you able to return it?! I think it's a great call out that they're not rated for side cold. The manufacturers are probably thinking that your shelter will cut down on the majority of the wind in a 4 season tent.
interesting experiment. I was thinking walk in freezer as well as some of the other comments. Are you not also missing some of the condensation from air warming in the tent? in the smaller space, your breath is warming it pretty well. Can't wait to see where you go from here.
I would have left the lid open, your warm air would have risen out of the freezer and the heavier cold air under you would have stayed in place. The reason you were hot is that a freezer doesn’t just freeze, it insulates as well. So all that 98.6F above the pad was being prevented from escaping, just like the 0F would be if you had a side of beef in there. I have a NEMO Sonic 0F from 2017 and it’s not a true 0F bag. I’d say the lower limit for me is 10F, but I’ve only used it with an Exped DownMat 9 LW which doesn’t seem to be nearly as warm as it’s rated for. My Xtherm was good at -10F with an overstuffed -10F bag. I was actually TOO warm.
Saw Justins trip to a glacier... He felt cold... I'll just stick to my Etherlight XT Extreme and NeoAir Xrherm NXT.... But interesting... Can't wait to see more real life testing...
maybe one of your subscribers can get you access to a meat processing plant, some of the cool rooms get down to -50c, that would be a good place to try out the equipment
I can't believe you slept in that with so small of an air gap. Id be afraid of co2 build up. We literally had training about inclosed spaces when I worked as an engineer at an aircraft depot. I have been inside aircraft wings with only enough room to pull my self through with my hands. Suffocating is a real threat even if there is an air opening. Cause the air is still stagnant
Great vidéo as usual :) Thank you for sharing ! Although I was wondering… Doesn’t the insulation in the pad enclosed on the side as well ? I am asking since I am not sure why the cold would be able to penetrate there more than all over the top and the bottom of the pad if it’s the case… What an I missing here ? :)
Good job for calling out the testing methodology’s of these companies for being faulty. They are definitely not an effective testing method. A controlled environment is never a situation that these pads are going to be used in, therefore they shouldn’t be designed for that.
a human body is a 200watt space heater. freezers are built to get a space cold and use their insulation to keep it cold. but they use only as much power as a light bulb! by putting a massive heater inside the cold room, you are running the machine completely out of spec, it could even kill it by overrunning it. depending on where the temp probes are and if it kept trying to cool during the attempt. they aren't made to run continuously, just enough to fight the bleed. alternatively it could have measured the cold below and just stopped cooling, leading to your overheating in the upper part. ultimately this setup wont work, but you could just freese a literal metric ton (1m^3) of water and put it into a kiddy pool and sleep on top of that.
Would unplugging the freezer make the difference? At that point, the freezer becomes a glorified ice chest since freon is no longer traveling through the walls.
Just rent a space in a logistics warehouse that has 100,000’s of square feet of freeze space at 0 or-10 degrees cascade designs is literally connected to a facility like that, no need for crazy contraptions that are warm on top and cold on bottom
Cold doesn’t travel. Hear travels. There is no cold and hot. There is heat and less heat. When you touch an ice cube - cold isn’t traveling to your finger - heat (energy) is leaving your finger.
When you closed the lid and started doing your ad, I had to say to myself "He survived to upload this video, so this isn't the saddest/creepiest ad read ever."
Holly shit Stephen!!! I have discovered you maybe only barely a YEAR ago?? Something like that?? And at the time you had like 24k subscribers!! And now you just SHOT UP to 224k??? Omg that's amazing mad!!! I LOVE your content Stephen and I constantly share with my boyfriend your amazing content!! This is one of those super cool, ultra dedicated type of crazy stuff you ever did!! I love it!! You are so cool in your approach to things!! I love watching you!! And make me wonna go hiking more!! Love from the UK 🇬🇧🇬🇧🇬🇧
*Gear in this video*
Nemo Tensor Extreme Conditions: geni.us/MXfqR
Therm-a-rest NXT Max: geni.us/pufSBjf
Nemo Sonic 0 Degree Bag: geni.us/bk902pj
Stephen, nice experiment and revised theory, but here's another thought. Your body heat overwhelmed the freezer capacity to cool its contents and heat rises, so the bottom was frozen and the top hot, and the slightly open door added to the effort.
I've written a few articles on walk-in freezers and coolers for restaurant use. These freezers and coolers can pull down the temperature on a 5 gallon (~22 liter) pot of soup to safe storage temps in a couple of hours. But those items are a passive temperature and not the active temperature a mammal uses. The main problem your experiment presented was a warm body in a small, artificially frozen space.
Your freezer was running overtime to cool your body, so the motor and coolant ran hotter in the area above the floor that mostly remained cold. Healthy, fed, live animals expend a prodigious amount of heat, especially humans.
As for losing hear through the sides, that's absolutely a good possibility if the sides are not insulated. But this was a good experiment and it points out the difficulties of cooling food products for safe storage as much as trading gear for outdoors enthusiasts keeping survivably warm in cold conditions. Thanks for giving this a trial run.
There is another variable to consider, and that's humidity. When you're outside in freezing temperatures the humidity is effectively zero, and unless you close yourself inside of a tent you'll have pretty low humidity throughout the night. But that's not how the freezer would work; your breath and evaporation from the heat of the body would thaw the water with nowhere to escape, creating a humid environment in which temperature will transfer much faster, not to mention the perceived temperature would be much lower.
And I think that would be an issue even with an industrial freezer, unless it's obscenely large for such a test.
Alternatively Steven could just take a trip to some place that has snow at this time of year and test there. It'd be expensive, but less than building or renting a huge freezer, and he'd get to experience actual real world conditions too.
Great points. And I feel @amunak_ also raised a valid point about humidity.
Last winter I camped on a beach in Washington in January. It was only +30F / -1C, but because the air was saturated with salt water, I could barely keep warm wearing all of my layers. No joke, I was warmer at -25F / -30C than I was in humid +30F / -1C with identical gear and layering.
I'm lucky, and happy, I decided to bring extra insulation. I only did so because I was worried about getting wet (always happens on the coast), not because of water content in the air.
Just for reference an average human with a dayly caloric need of 100kcal emits ~100w (~350btu) of heat, double if you are larger/heavyer and are reasonably trained.
That can easily overwhelm chest freezers since they are often highly insulated in combination with a small heatpump to be as energy efficiant as possible.
He was definitly burning up because the frezzer couldn't handle his boddy heat.
@@JustMikeHI found out the same when stationed in the southeast while in the army. It was just crazy that a resident of Maine who was regularly outside and active in temps well below 0F would be shivering while wearing every piece of gear he had at 35F, but the difference was
Also I suspect insulation. Those chest freezers have crazy amounts of insulation, so don't let the heat (or cold) escape that well, as well as someone pointed out above humiditiy. So I suspect that's why Stephen was really hot, and then was feeling cold of the pad because of the contrast of the two. May sound odd to say that a tent is better, but the evaporation would, whereas you would get a sort of heatbox effect in a freezer.
I saw the thumbnail and thought you might have spend the night in a walk-in freezer like a restaurant would have. Maybe you can fin a closed restaurant that you can contact the owners of to get permission and try it that way?
My thought too! At least not so claustrophobic!
Or the next day's special.
Yeah this video was unnecessarily complicated
That's a great idea!
I don't know if anyone would let him.
One issue with the ASTM rating system is the plates they apply are perfectly flat, when human bodies aren't. Your hip bones, butt, shoulders stick out more than the flat of your back, calfs, etc. This would give an un-even compression of the pad, and I suspect for most multi-layer designs, more compression = less loft = less insulation.
Yes i think it looked like he inflated the pads pretty well. In really cold conditions you got to do that and sacrifice some comfort
You need to make friends at a frozen food warehouse. (or just a larger restaurant / grocer ) a walk in freezer isn't the rarest thing around.
You separated the freezer into two micro climates by adding an insulated layer (the sleeping pad) midway through the space. The lower climate is pre-cooled (full of ice), any heat is being drawn away on three sides, and it's insulated from above. The upper climate contains an organic heater (you), and is being fed by warm air from the surrounding room (open lid).
This dramatic temperature differential between the two environments neatly demonstrates how effective the pad's insulation is.
Hi. I’m a theoretical physicist and have been modelling sleeping bags and sleeping pads, taking into account conduction, convection and heat radiation. Your experiment was really impressive and not a waste of time. The big issue is that the testing methods don’t take into account the fact that the body compresses certain areas of the pad more than others. In the majority of cases the body is warmer than the ground and so convection inside the pad shouldn't occur. Heat must rise from warmer lower temperatures to higher cooler temperatures, in order to convect. However, when the body depresses the pad, it produces a warm section under the body and the edges of the pad are actually higher and colder. Heat then convects from the base of the warm sleeper to the higher and cooler outsides. Modelling suggest that these side convection currents can be suppressed by having the long longitudinal chambers in the pad, as in most Expeds, and not short transverse chambers as in most Thermarests. I note that the Nemo Tensor has short transverse chambers. It’s a serious design flaw that doesn’t reveal itself in the tests.
Tell Nemo if they’re so confident in their products to sponsor a video with enough money that you can purchase a walk in freezer. You can become the sleep pad test guy.
good video. Some science experiments may fail but also reveal a weakness as you did with the potential of cold air infiltrating the side walls. I agree that really, the only way to test these things is to just go camping and use it as you would in the field. Real life, real answers. Lot's of variables, but you should be able to get a general feel for how it performs.
Justin found the same thing with new Tensor on glacier in Canada. Side cooling is a thing, whether irl or in freezer. Very likely an advantage for quilts that drape over the sides of pad. Or for Zen-bivy, who 'sheet' their pad. Meanwhile, pad-maker's are finally learning to suspend reflective layers, they have not yet solved the cold edge problem. ...they will. Perhaps, they will provide 'Trekology-style' tabs along the sides? Or pre-'sheet' the pad-edge? An internal vertical reflective layer or two just inside the edge is another possible approach?
I really appreciate your commitment and *inside* the *icebox* thinking! You've definitely given us a lot to think about when it comes to cold weather sleeping pads. Makes me want to finally pull the trigger on a winter hammock/under-quilt setup.
Please don't do this again without an CO2 and O2 warning system.
I appreciate you also took the time to show an experiment that did not go as expected. Some may think it was a failure, but showing what happened and why it didn't work as expected was very educational. THANK YOU for showing that.
Goodhart's Law: “When a measure becomes a target, it ceases to be a good measure.”
This is always the case once marketing has a number they can point to to say their product is better than competition. It does not matter if that number does not reflect the practicality of that measurement in a real world scenerio. Even when a company understands quality and practicality is what keeps existing customers, sometimes the goal of quality is lost to achieve that measurement as a target.
Seeing how Nemo stands up to this challenge will be interesting. At the very least it will show us what direction they intend to go as a company.
I agree designing for numbers isn’t good but this is better than what we had before where every brand just made up numbers based on whatever test they made up themselves. At least this way we have SOME consistency.
@@MyLifeOutdoors - totally agree!
If you want to try this again i wouls suggest looking at refrigerated trailer rental. Locally it would cost me 500 dollars for the minimum 3 day rental on a 6 by 10 trailer deaigned as a temporary fridge/freezer for restaurants.
Haven't seen this mentioned. Both freezers and refrigerators have heating elements. The rubber seals need good contacts to be air tight and thus are heated to melt ice that might form and yield a poor seal.
It's a bit pedantic but it's important to state that cold doesn't travel, heat does. Either in the form of radiation or conduction. Essentially these pads are baffled Ballons with space blankets inside. This system reflects heat back toward the sleeping surface and creates air gaps to reduce conduction through the pad. I think you're correct to seen the walls as a problem, active cooling on the sides. Normal condition inside a tent will mean rather stagnant air and so I'd expect comparatively minor heat loss to the cold air. Kind of like the difference in an air fryer to a conventional oven. The temperatures may be the same but the flowing air creates constant heat at the surface. Whereas conventional ovens see pockets of relatively cool air that surround the surface of whatever you're cooking.
Onto the localized coldness outside the chest: I wonder if the mattress conforming to your body causes contact between the reflective layers. I suspect that reducing the effective layers from 4 to 3 would cause a significant loss in local R value.
The idea that the pad may be conforming to my body and causing reflective layers to touch is an interesting hypothesis. And something the machine with flat plates couldn’t test.
Holy crap dude a freezer that's the size and shape of a coffin is where you're trying to sleep?!?!? This shows your commitment to your channel. Keep up the great work!
Please be careful. 💛
For Sale:
Large Freezer
Basically brand new, excellent condition, only slept in once.
Hopefully it's not disappointing like the ether light xt extreme. The r value was better than the xtherm but I slept cold when the weather was in the positives. Maybe this rating system needs to be revamped because as of now the xtherms feels like the only way to go. Thanks for testing these pads out. I watch every video of yours
I feel the same way. I want the Xtherm to be dethroned but I’d be lying to say I’m not skeptical. I’m meeting with Nemo’s director of quality next week to talk about their testing and hopefully find some (better) ways I can do some testing myself. We will see.
I’m honored! I’d love to connect sometime.
I'm almost certain I know why you had the issues you did, and weirdly, a better/easier/more accurate way to test.
I can see why you wanted to close the lid, but really what that did was to create an area where your exhalation warmed the space above you; since there wasn't much air circulation, you just wound up heating that space, and since a freezer is designed to insulate, well, you actually kept that space warm (insulation, with few exceptions, cares whether you're insulating to keep heat out or cold in).
So error number one was closing the door. Yes, I realize this means you'll generally get 'garage temp' above you, but...
Consider what you're really testing is the thermal transfer between the pad and your body. While the atmosphere above you might be warmer and skew your comfort overall, you'll absolutely be able to tell if there's a good thermal barrier between you and the ice.
If you wanted a more accurate full-on winter condition, you could rig some ducting under the ice, put a fan in the freezer, and pull the air gently through the ducting so that it's very cold, then shut the lid with a gap that is roughly the area of the ducting. That'll keep cold air circulating above you to better simulate the temperature.
As for the sides, while I take your point, the truth is that if it is freezing so is the air on the sides of the pad. I'm not sure I think that should be omitted as in real world conditions you'd have exposed/cold sides.
IMO the EXPED 7R (and others in that same series) are superior that they use down. There's certainly some oddities with that, and special care has to be taken about storage and use, but it does work incredibly well.
This, to me, highlights the importance of shelter choice in cold weather.
If you use a shelter where the fly doesn’t contact the floor on all sides, has a mesh only inner, or, worst of all, is too large of an internal volume for the occupant(s), you lose the benefits of a warmer microclimate within your tent, increasing the potential for this kind of issue being a reality.
I spent 4 nights between -8°c and -16°C last winter, with two nights being in 15inches of snow, and I was perfectly fine with my x-lite because I snow packed my 3.5 season tent and managed air-flow sensibly.
At those temps, condensation freezes to your fly and you just don’t need to worry about moisture internally if you layer down with a synthetic or primarily use synthetics.
During said trip, the inside of my tent was roughly 8-10°c warmer inside vs out and I slept like a baby, even on a pad not technically suitable.
You don’t always need the highest quality gear but you always need the highest quality information.
A+ for the effort, but as you found out it's not easy to crate real world test. I don't know what the problem is but a freezer have active cooling system that will suck out heat in a completely different way than when sleeping on the ground or snow. Actually, snow is a fairly good insulator so while it's cold to start with it wont lead the heat away. Same goes for ground while even when you slept on only the ice blocks you slept on something that has a both fairly high heat transfer coefficient and (while lower than water) also has a high specific heat capacity meaning that it can suck up a lot of body heat compared to ground/sand or snow.
You seem to know quite a few people in the industry so maybe you could get some hints from one of them on how to get your test more representative. In the freezer or on ice blocks.
Also, I think that your comments about the cold sides of the freezer are correct. They will transfer heat much better than the air you'll usually have on the sides of the mat.
Yeah, also if the freezer is detecting a warm item, or warm air coming in (wasn't a airtight seal obviously), it might be running on overdrive trying to bring the system down to temperature.
I am glad you took my advice and are making more videos where you risk getting hypothermic. 😂💪
It was great advice!
@@MyLifeOutdoors Your conclusion about cold coming from the sides is also why I place a foam pad on top of (instead of below) the air mattress in the winter.
Hi Steven, thank you for the effort to undertake the freezer test. I think you have correctly identified the failing in the R value measuring system. Exped make a pad that is filled with down, the Synmat, and therefore may not suffer heat transference from the side. Is there any chance you could experiment with a mat that uses a different structure to insulate, like the Synmat? (Apologies in advance for another poor nights sleep). Thanks again for your work to address this issue.
I took this pad to the Adirondacks in New York and spent a night in -11C. The pad performed very well and I was comfortable the entire night
All in the name of science!
I have used the xlite down to 5C with no problems but below it gets a little chilly. To boost performance I tried wrapping in a space blanket to avoid heat exchange at the sides and have been comfortable down to -5C.
Yes the 70g space blanket brings the xlite into xtherm territory but I don't have one. 😔
little off topic but man... nothing better than a nice warm night of sleep in the freezing cold. I love the smell of the air and the cold on my face then rolling over in the warm sleeping bag putting my face into the pillow. ahhh so nice hahaha.
I use an Invoker pad. It's heavy at 5lb. But under $100 rated a R9. It has a memory foam core so it needs to be rolled and strapped to the outside of the bag. But the extra weight is worth it to keep you alive and comfortable. It's also self inflating. Why you get ultra light for the rest of your gear.
I’ve heard Memory foam will freeze in cold weather. I guess it’s insulated enough on the outside?
Perfect timing! Just listened to you and Justin on the Backpacking Podcast talking about this. Then boom! Here’s the video! Sorry it didn’t work out, but as others have said, you’ve (we) learned a lot. Thanks Steve!
I used to work for REI and was able to see how they use a similar freezer with a sensor covered mannequin to do similar tests. BUT 2 differences. They were testing sleeping bags, not pads. At the time the thermarest pro lite plus pad was the standard used to test sleeping bags. Also, the mannequin doesn’t exhale warm air! Which I think was part of your problem.
Not a waste of money. Now you can store sides of beef.
Also, cold does not "go" anywhere. Cold is just the absence of heat energy. Meaning, the heat in your body was going down into the pad and out the sides, most of it probably above the first baffle, being in direct contact with a solid object that was being continually cooled down. But the cold was staying exactly where it was.
This is a really neat experiment, even if it didn't go quite as planned! As you have found, freezers like this can achieve very low temperatures but are not built with the expectation of a lot of active heat generation (I believe a human body is about 40W of heat when resting) happening inside the compartment and so struggle to keep up, and since the cooling coils snake through the walls it can generate a pretty unrealistic temperature profile throughout the body of the freezer.
If you can't track down a walk-in freezer or freezer warehouse nearby, I don't know if you have to give up on your chest freezer idea quite so quickly. Freezers like this are highly insulated boxes so they'll dramatically slow air exchange with the outside, which works in your favour to maintain a temperature differential with the outside. The freezer's own cooling is not actually that important here, so you should actually just turn the freezer off and use it as an insulated box. Rely instead only on the ice as your source of cooling; at least from the video, your ice was still mostly intact after the tests which means you have enough heat capacity there for an overnight test without the ice melting and letting the temperatures rise.
In terms of your temperature differential problem, the issue is air circulation. There's not much spare space around and with the open edge at the top, you have a massive difference in the bottom and top temperatures with no good way to equalize those. Adding a fan or two inside the freezer to drive air down to the cold space below you and equalize the air throughout the freezer would probably do a lot to ensure the below-pad and above-pad temperatures are much closer.
For the ventilation/suffocation aspect, look into Heat Recovery Ventilators. These are used in high-efficiency home design to exchange fresh air with the outside without losing all the heat/cold from inside the space, and you could drill a couple big holes in the lid of your freezer and install one of them with some ducting and fans to keep the air inside the freezer fresh/breathable while dramatically reducing the heat loss. You could then keep the freezer lid totally closed while still getting fresh (but pre-cooled) air, which would help massively with keeping the temperature inside the freezer well controlled.
Additional note: If you really need even more cooling power (I doubt it, with the above changes) then you could rig up a window AC unit to blow cold air in as well as they're much higher output than a freezer's normal compressor. This is a bit tricky though because it is hard to mount and direct the air in and you'd need to replace the controller with an aftermarket one to convince the AC to keep running at very low temperatures.
Some really good ideas here. Thanks
Very interesting. And nice to see MooseJaw getting some love. Love the Madness.
I spent 4 nights in -15°C in army issue gear and only lost feeling in both my big toes for 9 months. But it was fun! Like the frozen fleece masks in the mornings.
This does explain a lot, I felt something similar with my Big Agnes sleep system. I used the insulated q core with the pad the slides into the bottom of the sleeping bag. I try to counter-act with alpaca wool poncho wrapping around or sometimes inside.
I just bought the same system with the anvil horn sleeping bag, I think your idea of the wool type blanket is an excellent thought 👍👍
Bro just got a huge deep freezer on tax writeoff by using it for a video
Freeze the ice as you did, than take the plastic containers out of the freezer, and place a layer of wood on top of the plastic containers containing the ice. Than you stay there for an hour, measuring the temperature above and below the pad, which you obviously place above the wood slab. You do this with every pad to see how they perform.
Great video MyLifeIndoors! We should put danbecker inside as well to test gear!
Do you think snuggling with Dan Becker would have kept him warmer?! 😂
Ahahahahah
@@jamesfrancis9520 most likely yes, more than any quilt sleeping bag, or insulated sleeping pad!
@@edwin8808 what do you think Dan Beckers R-value is? Must be double digits!
Close the door with Dan Becker inside and lock it up.
I like it. Thinking outside the box!
Correction…inside the box 😂
That freezer was like one tight ass igloo (not Igloo as in the brand name coolers.). Your own breath also contributed to the warming effect in the dead air space inside the box, just like Inuit shelters do in the great white north. Real world conditions would have allowed for the heat build-up in your tent to dissipate through the walls of the shelter, reducing the temperature rapidly, allowing for more realistic interaction between your sleeping pad and your body. So, closing the lid on your “coffin” really skewed the results, as much as sleeping on hard frozen ice versus warmer, insulating snow did.
I’m new to your channel and just wanted to drop by to say a big THANK YOU for really testing out gear, going way out of your way to find their true performance and for shedding light on less known and less conventional gear/equipment. I have thoroughly enjoyed your videos like tents set up on top of your car and this one sleeping in a coffin sized freezer LMAO 😂 These beat any Netflix movie. Binge watching over the holidays!
Chest freezers are dope and super efficient. Put a bunch of food in it and you'll always have something good to eat and won't have to go grocery shopping as often.
I was in a tent that was ripped apart by the wind in driving rain, hail and sleet. We awaited out the night with no sleeping bag and just our hiking gear on our sleeping mats. Mine was a Sea To Summit and I never felt the cold through the mat, only from the air.
Could you suggest the best value, lightweight, storm tent?
The winds were above 120km/hr and temps down to 0°C
This experiment is actually very helpful and might explain why I sometimes experience cold coming through the sleeping pad when using it in a hammock.
Technology Connections has a good video that may explain why your freezer acted that way. It's likely part of the frost free design and should cycle over to cooling given enough time.
What about the xtherm outside the freezer on the ice comparison?
So if you are really committed to this project, you could build a slightly larger cold room with a couple layers of 4" foam and use the freezer's guts to cool it. All you'd need to do is vent the condenser side of the circuit out of the "room". But this all requires that the compressor can handle more heat than your body puts out, otherwise you will overrun the thing.
Talk about commitment!
I have spent a night in a large freezer-room, to test gear for an expedition in the Arctic. Usually I can handle -20 C with ease, but in this case, I struggled. Probably because of the moisture building up in the room, creeping into my sleeping bag, even when using a vapour barrier liner. Breathing was uncomfortable as well..
Pretty cool way to try something out. A large walk-in freezer would be better suited for your experiment, but I think lawyers and liabilities would keep business owners from letting you try out gear in there.
I've spent the night at -17F up in Michigan's UP. Not only can it get really cold, but the humidity also affects the perception of cold. I know Alaska gets freaky cold, but it's also extremely dry.
Come out to the UP! Extreme conditions gear testing, tons of beautiful winter hiking and skiing, all wrapped up in one great location.
I believe that you are correct in your assessments.
What I found that worked very well was to have a torso length piece of the blue closed cell foam pad on top of the air pad. It was the only way the air pad was warm enough. At the time I assume that was because of the poor performance of the sides of the air pad. For reference I had the original Big Agnes Insulated air pad and the temperature was 25 degrees all night. I used a synthetic quilt with just under 2 inches of loft.
I hope you get a refund, or get very into meal prep
It may or may not have contributed to this experiment, but the side-to-side movement of air absolutely contributes to a colder feeling pad. This is exacerbated with movement. Some pads do a better job than others at isolating and deadening this internal air movement. This is a blind spot in the ASTM testing method.
I love to see Moosejaw sponsoring your videos!
Damn you should've taken that freezer money and taken a trip to the Arctic instead.
"What We Do in the Shadows"🧛
Did you want the freezer to keep other items frozen or were you able to return it?! I think it's a great call out that they're not rated for side cold. The manufacturers are probably thinking that your shelter will cut down on the majority of the wind in a 4 season tent.
Convert it to a cold plunge setup
interesting experiment. I was thinking walk in freezer as well as some of the other comments. Are you not also missing some of the condensation from air warming in the tent? in the smaller space, your breath is warming it pretty well. Can't wait to see where you go from here.
I hope you and your wife are getting along 😊
Lol purchasing that freezer probably got you out on some watch list. Love the dedication!
Haha! It’s for sale if you want it. No watch lists involved 😂
"Coffin sized freezer. Only used once"
10/10 commitment and ingenuity and derring-do
Have you tried the Klymat inflatable light? it has a magnet and a strap and dims .. It's pretty cool for seeing in dark places.. like freezers
Well done. Thank you.
I would have left the lid open, your warm air would have risen out of the freezer and the heavier cold air under you would have stayed in place. The reason you were hot is that a freezer doesn’t just freeze, it insulates as well. So all that 98.6F above the pad was being prevented from escaping, just like the 0F would be if you had a side of beef in there.
I have a NEMO Sonic 0F from 2017 and it’s not a true 0F bag. I’d say the lower limit for me is 10F, but I’ve only used it with an Exped DownMat 9 LW which doesn’t seem to be nearly as warm as it’s rated for. My Xtherm was good at -10F with an overstuffed -10F bag. I was actually TOO warm.
Man this content is CLUTCH. I love videos like this lmao
Ah, what you really needed was a SnugPak Antarctic mad beneath the mat as well. 😉
You should find a sleazy restaurant employee that will let you sleep in their walk in freezer.
Saw Justins trip to a glacier... He felt cold...
I'll just stick to my Etherlight XT Extreme and NeoAir Xrherm NXT.... But interesting...
Can't wait to see more real life testing...
This is a brilliant idea for this video.
Wonderful video! Thank you!
Curious if you’ll be testing a bunch of other pads with this method!
That was the plan until I ran into problems
thanks for thinking outside the "box" to try to get us useful info.
This was cool, hey now you can get into hunting maybe and now you have a freezer to store a lot of good wild meat!
maybe one of your subscribers can get you access to a meat processing plant, some of the cool rooms get down to -50c, that would be a good place to try out the equipment
That's completely nuts!!
Where in the freezer is temperature measured - or how does the freezer regulate the temp? Upper half was insulated from the lower half.
Now you just need to fill that freezer with popsicles. Thanks for the video.
you are a wild man for even trying this
I can't believe you slept in that with so small of an air gap. Id be afraid of co2 build up. We literally had training about inclosed spaces when I worked as an engineer at an aircraft depot. I have been inside aircraft wings with only enough room to pull my self through with my hands. Suffocating is a real threat even if there is an air opening. Cause the air is still stagnant
Great vidéo as usual :)
Thank you for sharing !
Although I was wondering…
Doesn’t the insulation in the pad enclosed on the side as well ?
I am asking since I am not sure why the cold would be able to penetrate there more than all over the top and the bottom of the pad if it’s the case…
What an I missing here ?
:)
No. The sides of any pad is its weak-point.
"Coffin sized freezer. Only used once"
(That's going to be one interesting Craigslist ad)
Your freezer is way too small. You need to find someone with a walk-in freezer for you to test in.
This is a really cool video! I was curious about the side air flow.
Interesting experiment, I opened up my house to cool it down to ambient so I could try my Nemo bag for a week. I couldn’t sleep in a freezer.
Good job for calling out the testing methodology’s of these companies for being faulty. They are definitely not an effective testing method. A controlled environment is never a situation that these pads are going to be used in, therefore they shouldn’t be designed for that.
I wish you were wearing a count Dracula suit when you came out of that freezer.🤣🤣🤣🤣
a human body is a 200watt space heater. freezers are built to get a space cold and use their insulation to keep it cold. but they use only as much power as a light bulb! by putting a massive heater inside the cold room, you are running the machine completely out of spec, it could even kill it by overrunning it. depending on where the temp probes are and if it kept trying to cool during the attempt. they aren't made to run continuously, just enough to fight the bleed. alternatively it could have measured the cold below and just stopped cooling, leading to your overheating in the upper part.
ultimately this setup wont work, but you could just freese a literal metric ton (1m^3) of water and put it into a kiddy pool and sleep on top of that.
Would unplugging the freezer make the difference? At that point, the freezer becomes a glorified ice chest since freon is no longer traveling through the walls.
Interesting experiment!
Anyone seeing this thumbnail knows the video is going to be fire
Just rent a space in a logistics warehouse that has 100,000’s of square feet of freeze space at 0 or-10 degrees cascade designs is literally connected to a facility like that, no need for crazy contraptions that are warm on top and cold on bottom
Cold doesn’t travel. Hear travels.
There is no cold and hot. There is heat and less heat.
When you touch an ice cube - cold isn’t traveling to your finger - heat (energy) is leaving your finger.
When you closed the lid and started doing your ad, I had to say to myself "He survived to upload this video, so this isn't the saddest/creepiest ad read ever."
“Good morning. Well that was a really interesting night inside the freezer.” 😅 From things you would never expect to hear from a hiking gear test.
Ha! Glad you enjoyed it
Dinwoody glacier is just a 5 hour drive and a 2 day hike in!!!!
Holly shit Stephen!!! I have discovered you maybe only barely a YEAR ago?? Something like that?? And at the time you had like 24k subscribers!! And now you just SHOT UP to 224k??? Omg that's amazing mad!!!
I LOVE your content Stephen and I constantly share with my boyfriend your amazing content!!
This is one of those super cool, ultra dedicated type of crazy stuff you ever did!! I love it!! You are so cool in your approach to things!! I love watching you!! And make me wonna go hiking more!!
Love from the UK 🇬🇧🇬🇧🇬🇧
Hey Stephen, could you do a video about wearing glasses and outdoors? I have to wear glasses too and it sucks.
Instead of sleeping you can just throw a temperature data logger there.
This is absolutely the most bonkers gear test I have ever seen. 😂❤
This is how you get people interested in science regarding terms like exothermal and heat transfer. Haha. I enjoyed this experiment.