How can I protect my kids from frostbite?

DEAR DOCTOR K: My kids love to play outside, even in the cold and snow. How can I protect them from frostbite?
DEAR READER: Frostbite, ironically, results from the body's attempt to protect itself against the cold. Our body cares much more about the temperature of its inside self than the temperature of its outer self. What do I mean? The normal temperature inside our body (our "core temperature") is around 98.6 F. The organs inside -- the brain, heart, lungs, liver, kidneys and others -- function best at that temperature.