Though I do not use them on a regular bases I keep a few in my ski bag; just in case. The temperatures around here are relatively mild and dressing appropriately usually keeps me warm enough. However when the temps drop to close or below Zero these puppies can really save your skin.
Over the years I have learned a few things about hand warmers that you might not know. Tips on how to use them and ways to make them more effective. There are also several different types of warmers that I will share in following post.
Chemical type hand warms are made by many different companies. They also come in various different forms, such as toe, foot and sleeping bag warmers. These type of chemical heaters are activated by oxygen, once you open the package, the heater is exposed to air and a reaction begins. When the reaction is done, the warmer becomes hard.
-Since warmers last for many hours (7 hours according to some packages), and your outing might not, you can save your hand warmer by placing them in an air tight zip lock baggy. This will stop the chemical reaction. You can then save the heater for the next time you need it again. Make sure to suck all the air out of the bag before you seal it.
-when buying heaters, give the packet a squeeze. The material in the packet should be loose, like a bag of sand. Often the outer wrap develops a hole, and the warmer becomes activated and is already spent even before you get a chance to use it. Also check it before you pack a warmer with you off on your adventure. It is a real bummer to have an ineffective warmer to fall back on.
-some gloves have little zippered pockets. These are for your hand warmers to be placed in. Very effective.
-Skiing is the only time that I have needed toe warmers. In fact toe warmers are so effective that I have never needed foot warmers. Toe warmers are triangular shaped warmers that have a sticky pad on them. The directions tell you to stick the pad on the foot bed of your boots. I have found that placing them on the foot bed negatively effects the way you ski or walk. Instead place them on top of your toes. There is usually space in your boot above your toes to spare. This also makes is easy to insert and remove.
-Since the warmers need air to heat, sometime they become oxygen starved and do not produce the optimal heat output. Glove pockets and zipped up pockets often do not have enough air flow. Remove the warmers from your pocket if you suspect that they are not working effectively and give them a shake and replace. You might get a little more juice out of them.