These HotHands Toe Warmers are single-use air-activated heat packs. You can use them for keeping your feet toasty when the temperature gets cold. These air-activated heat packs provide safe, natural warmth so you can enjoy the outdoors all year long. They feature an ultra-thin design and rounded shape that offers optimal comfort in both boots and shoes. These warmers also include adhesive to hold them in place and contain activated charcoal to absorb and reduce odors. Each one provides up to eight hours of heat.