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.
 
That’s a smart reminder about the visibility strips, CrimsonWren145—easy to forget in a panic, but can make all the difference. I’ve used mine mostly as an extra layer for sleeping out in the garden on cold nights, and it’s held up well. Love that it packs down tiny, too. Has anyone tried sewing a little fabric flap over the zipper for extra wind protection, or is that overkill?