Hand warmers are handy (excuse the pun) little low tech devices that can add a layer of comfort to your preparations or just help out on a day of outdoor recreation in the cold (skiing, snowshoeing, ice fishing, etc.). The original hand warmers are a thin pouch of papery material that feels soft like fabric. Inside the pouch is a concoction of iron powder, water, salt, activated charcoal, and vermiculite.
To use your hand warmers, open the packet they are sold in and expose the warmers to the air. The air reacts with the iron powder in the hand warmer and oxidizes, creating heat. This heat can be carried in your pockets, slipped in your gloves or your boots, tossed in a sleeping bag, etc. They are made in different shapes and sizes–standard rectangles for hand warmers, half circle shaped with adhesive for toe warmers (to stick to the inside of your shoes or boots), and large rectangles for body warmers. Depending on the size and brand you purchase, these warmers can last anywhere from 5 to 12 hours.
The hand warmers can heat up to 135 degrees Fahrenheit, which is pretty darn warm. If you’re using them with small children, make sure they’re not right up against their skin at any time.
They are designed for a one time use, but because they work by reacting with oxygen, the usage time can be “paused” by putting them in an airtight container (preferably vacuum packed to remove any extra oxygen from their environment). They can then continue to work when they are removed from the air tight container at a later time.
I do NOT like being cold, so I love these little things. I have used hand warmers on outings to fetch the Christmas tree, caroling, winter hiking, checking bear dens in the winter for college research, in my baby’s snowsuit toes (protected by a bit of extra padding), in my kids’ pockets, and in my sleeping bag on a cold camping night. Hand warmers are a useful item to have on hand, providing comfort and warmth any time you are dealing with cold.