hand warmer

Hand warmers are small (mostly disposable) packets which are held in the hand and produce heat on demand to warm cold hands. They are commonly used in outdoor activities such as hiking and skiing to keep extremities warm and assist insulated clothing. Other types of warmers are available to provide soothing heat for muscular or joint aches. Depending on the type and the source of heat, hand warmers can last from 30 minutes (recrystallisation) up to 24 hours (platinum catalyst).