Instant hand warmers are great--just shake 'em up, and you've got spontaneous warmth to thaw your hands during the cold winter months. But they're awfully expensive, and not because they're complicated to manufacture. In fact, you can make them yourself in a few very easy steps.

Materials

Calcium chloride ice-melt pellets

Water

Two ziploc bags of different sizes

Instructions

1. Fill a large ziplock bag one quarter of the way full with calcium chloride ice-melt pellets (available at most hardware stores).

Greg Maxson

Hand Warmers 1

2. Fill a smaller ziplock bag halfway with water, close tight, and place inside the first bag.

Greg Maxson

Hand Warmers 2

3. Squeeze the smaller bag until it breaks open, to create a heat-producing reaction that will last 20 to 60 minutes.