You hit the nail on the head with your analysis. However, in the future, try testing for a longer period of time. What I and others have found is that the bivy keeps you surprisingly warm for about an hour. Then you will be chilly, but ok, for about another hour. Then at that point heat loss from conduction overwhelms heat retention by blocking convection and radiance and you will be freezing cold. It really isn't an overnight solution (not surprising since the original use case was to keep marathon runners warm after a race and then the military started using a thicker version as a trauma blanket for keeping soldiers warm during medivac). The other issue is that since they don't breathe you will get wet from perspiration and then have an immediate issue with evaporative cooling once you exit the bivy. A better emergency solution IMO is the sitting bivy using a rain poncho (bringing your arms, legs, and head inside) and then lighting a small candle to create what's known as a Palmer Furnace.

Pretty sure these saved my life once. so I swear by having some of them for the price. Got stuck in a cold rain in the fall overnight unexpectedly. I don’t think I would have made it without them.

Seems like a 2 piece suit one with a poncho top, compass, whistle & pocket for the win. & some kind of back /kiester pad. 😉

I've never actually paid attention to these products in other vids, thank you for demonstrating the differences between the blankets and the bivvys.

They also work great for reflecting light if you are growing produce indoors. Just wrap around the outside of the shelf you are growing on or tape to the wall behind and it will reflect light back. It can make a Big difference especially with sprouts.

1. Take two identical hot water bottles and fill them both up with hot water fresh from the kettle. 2. Place one bottle inside the mylar sheet and the other some distance away from the first 3. Log the temperature at every water bottle, create a graph and calculate the difference. Additionally test the milar sheet for a short time on yourself to find out how practical it is (the unfolding you mentioned).

Awesome video. Thanks for sharing.

Just came across your channel. I enjoyed the review.

Great video! I love your channel! I think you'll grow fast!

Our heater went out last winter for 3 days. Thankfully we had 2 small space heaters, which actually kept the temp. above 53 inside. The first night, it dropped to -25 (f), and the apartment cooled down to just above 40. I took 2 of the Mylar blankets, and placed one under the bottom sheet, and the other above the top sheet, added a wool blanket and a heavy comforter. I also used a heating pad and warmed the foot area of my bed. That kept me nice and warm through the night, (not sure of what the temps were under there). If you have ever opened the box on a Hot Pocket, the interior is silver, which radiates the heat from the microwave all around. Pretty much this is what those 2 blankets did. It kept the heat trapped inside the blankets and kept me warm and comfortable. (I am too old to be getting out in the snow to camp.)

Won't work on cold ground, reflective radiant insulation requires an air gap to work, put an air pad inside that bivy to serve as air gap and store radiant heat from your body. If you can still fit in the bivy, OK, if not get a second one.

I just found your channel and am really enjoying your videos. I very much enjoy your positive vibe compared to other channels in the prepping space. Do you think there would be much benefit if you were to double up on the Mylar bivies and wear two of them?

I've seen so many different types of blankets out there. Which one were you using in this video? Many of what is out there for around $1 are poorly rated, mainly for being transparent and tearing easily- but yours did not look that way and looked better built.

Very good review. Tank you and best of luck to you.

How does a sol escape bivi compare being $40 ish maybe more it is not breathable but it it any warmer ? Also loads of things you can make with them from under blanket formyou hammock to foot warmed insulted for you boots just need a knife and cut around you foot shape help protect your from the snowly ground looking forward to more of these in the future

Nice test! Did you end up medium rare? The flimsy spaceblanket belongs in your medkit, to keep people warm and prevent them from going in to shock. You know where to find it if you need it in a pinch.

Have you tried a blizzard bag or blizzard coat? Spendy but awesome.

Helsport Fjellduk, Jerven Fjellduken or something similiar mountain cape style multifunctional piece of gear can be an option when you know you are going to need atleast some of its functions, just for emergencies it is bit heavy and pricey. But when considering the price Helsport contains so many seams,YKK zippers and grommets that it cannot be a cheap iten to manufacture either. Anyways that might be something You'd like to test. For the windy and rainy conditions and for motorcycling/hiking trips it can be quite an usefull thing.

How does the SOL emergency bivvy compare?

> keep you alive Ahem, misinformation. Condensation leads to temperature drop, and possible hypothermia (early morning condensation plus moisture evaporating from the body). The leakage on the blanket version however is favourable as it will still condense but less noticeably. Hence premium bivvies are made with "breathable" material. Good video otherwise, and thanks for sharing your testing.

All made from the same material all made from the same factory just different colors and they have a different seller's name on it they're all made out of the mylar material and all made the same place

I got second-hand embarrassment watching this

Yup. Whiney...