Most any winter sports enthusiast has used them (or at least received them as a gift): hand and toe warmers. Throw one of those little packs in your pocket and you'll get a few hours of warmth. Problem is, the minute that warmth expires, the pack is useless.
With outdoor gear of every stripe going green, it's not surprising to see reusable hand warmers. While at the Outdoor Retailer show, I saw two different designs:
The more interesting of the two reusable hand warmers, Wonder Warmers are pouches with liquid inside. When you press the metal disk inside, it causes a chemical reaction that solidifies the solution and causes it to heat to around 130 F. The packs provide 30 minutes to 2 hours of cooling, depending upon size. To recharge, you simply place the pack in boiling water for five to 12 minutes. You can reuse 100 or more times, according to company literature.
WonderWarmers come in various shapes and sizes including pocket-sized pouches and therapeutic wraps. Prices start at $12.
Pros: Virtually unlimited number of uses
Cons: Short warmth time frame, cannot recharge outside
Grabber 10 Hour Deluxe Handwarmers
Grabber, an established manufacturer of hand warmers and cooling products, also has reusable hand warmers. Its warmers provide up to 10 hours of heating and can be "turned on" and "turned off" so you can use those hours whenever you want. To activate, simply take the hand warmer out of its bag and expose to air. To "turn off" put it back in the included zipper bag and close shut. Then you can use whatever remaining time you have left in the future. $4 per 3 pairs at REI.
Pros: 10 hours is plenty for the average winter day, low price
Cons: Cannot reuse once the 10 hours is up