When the skin is red and stinging from the cold you should warm it to prevent further damage. When the outer layer of skin freezes it may be mottled and turn white or grayish in color and waxy in appearance. Do not rub the skin as it will cause more damage by sending ice particles into deeper tissue. It is okay to warm your hands and place them gently on the frostbitten area to thaw it out, however do not let it re-freeze. If your hands or fingers are frostbitten hold them under your arms to warm them but do not massage.
Deeper frostbite occurs when the lower layers of tissue also freeze.
There may be pain, but in some cases of real deep frostbite there is no pain due to nerve damage. This condition is very serious and the frozen tissue may slough off when thawed. If this type of frostbite occurs it is best to leave the tissue frozen and get the victim to the hospital as quickly as possible. The biggest danger comes when you slightly thaw frostbitten flesh and then let it re-freeze. They most frequently occur on slopes of between 20 and 60 degrees, and especially between 30 and 45 degrees, usually within 24 hours of a snow fall.