Amazon Portable Emergency Blanket & Bivvy Sack Thermal Sleeping Bag - 2 Pack $13.52 @Amazon

Interesting how much mileage folks are getting out of these little bivvy sacks. I keep one in my gardening bag too—not just for emergencies, but sometimes just to sit on damp ground or wrap plants during a surprise cold snap. Condensation is definitely real if you’re zipped up tight for a while, but it’s sort of the nature of the material. I’ve found cracking the top open a smidge helps, though you lose a bit of heat.

The crinkly Mylar noise doesn’t really bother me unless I’m trying to sleep outside—then every move sounds like a snack wrapper in a movie theater! But I guess if you really need the warmth, you just deal with it. As for durability, mine’s lasted through a couple of rough garden days, plus a camping weekend, no tears yet. It fits in the side pocket of my backpack and barely weighs more than a packet of seeds.

Curious, though—has anyone actually spent a full night sleeping inside one of these, in the rain? Wondering if it really keeps the water out or if you eventually get soggy anyway.