I few years ago I bought HOT HANDS-2 hand warmers at Walmart for my mother-inlaw. The web address for the product is heatmax.com.

You open the outer package and shake the inner package to start the heating process. The package says "up to 10 hours of heat. The average temperature is 126-144 F (52-62 C). The contents are Iron powder, water, salt, activated charcoal and vermiculite.

There are several warnings on the package.

1. Don't use if you have sensitive skin or can't feel heat.
2. Consult your physician before using if you have allergies, diabetes, frostbite, open wounds, circulatory problems or scars.

"HotHands-2 Hand Warmers provide you warmth and freedom to endure cold climate situations. The product is used by professional athletes, outdoor sportsmen, spectators, skiers and those who want safe, convenient, concentrated warmth."