HotHands Hand Warmers

HotHands Hand Warmers are air-activated, single-use heat packs that come two to a pack, each individually sealed. They need no charging and provide up to 10 hours of heat, so they are handy outdoors, on a commute, while traveling, or stashed in a car or emergency kit. They are made with iron powder, water, salt, activated charcoal, and vermiculite, and the maker notes they are TSA-approved for air travel. HotHands states its warmers are "MADE IN THE USA Using Domestic and Imported Materials."