Packed a couple of these for a cold camping trip and was honestly surprised how much heat they trapped — the metallic side really does reflect your body heat back at you. They crinkle like crazy and feel flimsy, but for something disposable that folds down to pocket size, that's fine by me.
Alexander★★★★★
Kept one of these in my car all winter and finally used it when I got stuck waiting for a tow in 20-degree weather. Wrapped it around my shoulders and was genuinely surprised how fast I stopped shivering, since it supposedly traps over 90% of your body heat. Twelve in a pack for this price is a stea
Eli A.★★★★☆
The metallic surface really does retain over 90% of your body heat as advertised. It’s a bit crinkly and not reusable, but for emergencies or camping it’s perfectly fine.