Frostbite is damage to body tissue caused by that tissue being frozen. Frostbite causes a loss of feeling and a white or pale appearance in extremities, such as fingers, toes, ear lobes, or the tip of the nose. If symptoms are detected, get medical help immediately! If you must wait for help, slowly re-warm the affected areas. However, if the person is also showing signs of hypothermia, warm the body core before the extremities.
At a Wind Chill Temperature of minus 50F, frostbite will occur within 10 minutes! At minus 30F, frostbite will occur within 30 minutes!
The warning signs of hypothermia, low body temperature, are uncontrollable shivering, memory loss, disorientation, incoherence, slurred speech, drowsiness, and apparent exhaustion. If these systems are observed, take the person's temperature. If it is below 95F (35C), seek medical care immediately! If medical care is not available, begin warming the person slowly. Do not warm extremities (arms and legs) first! This drives the cold blood toward the heart and can lead to heart failure. Instead, warm the body core first. If needed, use your own body heat to help. Get the person into dry clothing and wrap them in a warm blanket, covering the head and neck. Do not give the person alcohol, drugs, coffee, or any hot beverage or food. Warm broth is better.
For more information on the dangers of extreme cold, as well as a wind chill chart, visit: http://www.nws.noaa.gov/om/windchill/index.shtml