What is great about this bag is that 1) it's smaller and lighter than just about any other sleeping bag, 2) it's an actual piece of gear, unlike the very thin emergency blankets you can tear easily, and 3) it can be used as a bivy sack to raise the temperature of any other sleeping system. So this final point is to say that you can put your blankets or other sleeping bag inside of this bag, or this bag inside your other sleeping system, and significantly raise your temperature and comfort level over night. In this way, I think this bag could be a real life saver at low temperature.
What I learned from sleeping out in this bag:
● You will die of suffocation if you do what you'd do in a sleeping bag and pull your head inside and close up the top of the bag. Keep in mind that this is a glorified, human-sized trash bag -- actually, it's a lot like a body bag -- so you'll suffocate in this bag if you try to breath in it. This means that I wore my heavy winter jacket to bed, as air infiltration was a problem around my neck and shoulders, and a winter hat was essential to staying warm.
● Bunching up in a fetal position (on my side) and pulling the bottom of the bag up and under me kept me the warmest. Less area to heat and heat consolidation worked out.
● This bag does not breath like a GoreTex bivy sack or regular sleeping bag. This means that moisture built up in the bag over night. In a survival situation, that wouldn't bother me one bit as I'd be alive to complain about the moisture in the morning. But as a piece of backpacking gear, say, you'll want to note that you will have to dry this bag out during the daytime hours just to keep it from remaining wet.
● The temperature inside the bag was bearable, even down around freezing. This was in a tent with all the flaps open, as I wanted to see how cold I could stand it. Note that I was on a sleeping pad, and the ground was the coldest thing to deal with.
● A small point, but this bag is noisy when you move around. I found I woke myself up as I moved around. Sleeping in this bag with others in a tent would probably drive them nuts.
● Re-packing this bag tight enough to fit back in its stuff sack takes some practice. I found you had to roll it very tightly from the bottom, then unroll and fold it to get it to fit. When it is back in the sack, though, it's pretty compact.
As I mention in my video, I'm glad to have this bag even though I know it has some limitations. I will keep it with my emergency supplies and rest assured that it's there. I also could see taking it on summer trips to the high-country so I could take only my lightest sleeping bag but have this backup (as a bivy sack to go over my sleeping bag) for very cold nights at high altitude. It's tough enough that I'm not afraid of wearing holes in it or ripping it or anything like that.
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This product was NOT given to me as part of any promotion. I bought it after doing some comparison shopping and this review is entirely the result of my own opinions and use of the product.