Providing up to 18 hours of 130F to 140F heat, the HotHands Body and Hand Super Warmer delivers a safe and easy-to-use pack that keeps your hands warm when the temperature gets cold. Air-activated packs are formulated to deliver a constant, comforting heat. Ultra-thin, rectangular pack fits into shoes, gloves, and other spots needing a shot of warmth easily. Made in USA.Per 10. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Hand Warmers.