Pocket oven for warm hands.
The Relags hand warmer is a small pocket stove that generates heat with the help of charcoal sticks. The stick is lit (on both sides if it is very cold) and ensures that the can is pleasantly warm, but not too warm. If you are very active, you should secure the can to prevent it from being opened accidentally. Now you have warm hands or whatever part of your body you want to warm for up to four hours.