Adventure Medical Kit's Escape Lite bivy is constructed from a breathable water resistant fabric that's silvered on the inside. The 'feel' of the fabric is like paper that's been continually scrunched so that its flexible - and of course its much tougher than paper - so sleeping in it is different but not unpleasant!

I own and have used SOL’s much less expensive Sol Emergency Bivvy, which is non-breathable and functions as a vapor barrier. My questions upon receiving the Escape Pro Bivvy were: Although you can sleep in just a bivvy bag, it’s generally a pretty unpleasant experience – both should be used in combination. In all but the warmest weather you would feel uncomfortable and cold without a sleeping bag once the sun has gone down.

Using the Escape Pro Bivvy as a sleeping bag cover or liner are two suggested uses in the product materials, but I found it to not do either of them well. I only used it for a night, but in a multi-day survival situation the amount of condensation could be dangerous or even life threatening, if there was no way to get the sleeping bag and bivy dry every day. I only tested it in the -10 to -15 range, and it is possible with the right bag and outside temperature there would be less condensation, but as this is meant to be a survival bag, it should work in relatively mild winter conditions such as this. As a liner, it does add warmth, but it also removes all of the coziness of slipping into a comfy, fluffy sleeping bag. With my 40 degree Marmot Atom and the SOL Escape Bivvy, I would say I had an extra 5 degrees to work with. Pretty much when it hit 35 or below, I was shivering. I would say if you plan to use this bivvy in colder conditions, you should consider a sleeping bag with a lower temperature rating. Note: I don’t have much meat on my bones. As a product its really dual use - if you decide that you need an emergency bivy option this one would allow you to uprate your sleeping bag by using it as a liner which will offset some of its weight (since you don't need to carry a silk liner), then if its not needed as an emergency bivy then carrying it has still brought some benefit.

No idea why others have reviewed this negatively. Maybe they are really big...? Not used to UL gear? I'm 5'6" and 160. This bivy is small. Adventure Medical Kit's SOL Escape Lite bivy is an emergency bivy that is breathable - it can be used as a sleeping bag liner to uprate your bag when not required in an emergency situation. All in all I can say that the escape bivvy bag is probably one of the best, if not the best bivvy bag available even though it has a few little flaws. A bivvy that BREATHES, keeping you dry from the inside out. Highly weather resistant so you stay dry in any conditions. The SOL Escape Bivvy is categorized as an emergency bivvy, with the usability for an ultra light sleep system. The bag is made out of a thin water resistant fabric with microporous to give it its breathable capabilities. It comes with a reflective interior that helps retain 70% of your body heat, and the seams are waterproof, ensuring heat stays in and the elements stay out.The complaint with most ultra-light emergency shelters is the same: condensation builds up inside as you get warm, leaving your clothes soaking wet. Low weight and a compact shape are the most important factors for runners, since a bulky or heavy bag makes running feel awkward and also more strenuous. Is a bivvy better than a tent?

THERMAREST & MSR: Sale! 30% Off all MSR Tents and Thermarest Sleeping Bags including the award-winning Parsec 0!Went on a Junior Forest Wardens outing in a Wall Tent with temperatures at -15°C. As there was not enough room in the tent for everyone I took the opportunity to sleep outside in a down mummy bag and the Sol Escape bivy.