These are pocket hand warmers. You put them in the microwave for 20 seconds, then put them in your pockets to keep your hands warm.
I got the pattern here:
http://www.thesewingrepublic.com/pro...etHandWarmers/
You can make a pair of these in less than an hour. The pattern as written is big enough for a child or a woman's hands, but for larger hands, I made them a little bigger. The main squares are 6 1/2-inches square, and the pocket rectangle is 6 1/2 x 10 inches. Then I added 3/4 cup of rice instead of 1/2 cup.
I'm making three more pairs. One for each of my boys, one for my husband, one for my DIL, one for my walking buddy, and one for me!