At Christmastime, Jack Frost nipping at your nose sounds cute. When you are shoveling snow in January, you worry about meeting his ugly cousin, frostbite.
While hypothermia, the lowering of core body temperature, is deadly, frostbite---freezing of the skin and underlying tissues--- can cause permanent tissue damage, as well as lead to amputation and disability. The Mayo Clinic reports there are three stages of frostbite.
Frostnip, the first stage of frostbite, doesn't cause permanent skin damage. With this mild form of frostbite, your skin pales or turns red and feels very cold. Continued exposure leads to prickling and numbness in the affected area. As your skin warms, you may feel pain and tingling.You can treat very mild frostbite with first-aid measures, including rewarming your skin.
The second stage of frostbite, called superficial, appears as reddened skin that turns white or pale. You may notice stinging, burning and swelling. A fluid-filled blister may appear 24 to 36 hours after rewarming the skin. This requires medical attention.
As frostbite progresses to the severe, deep, stage, it affects all layers of the skin, including the tissues that lie below. You may experience numbness, losing all sensation of cold, pain or discomfort in the affected area. Large blisters form 24 to 48 hours after rewarming. Afterward, the area turns black and hard as the tissue dies. This obviously requires medical attention and may result in hospitalization as patients struggle with mobility during the healing process.
Risk factors for frostbite include conditions that affect circulation, such as diabetes, and prolonged exposure to cold.
Resources:
https://www.cdc.gov/nchs/data/nhsr/nhsr076.pdf
https://www.cdc.gov/mmwr/preview/mmwrhtml/00000654.htm
http://www.mayoclinic.org/diseases-conditions/frostbite/basics/definition/con-20034608
http://www.mayoclinic.org/diseases-conditions/frostbite/basics/symptoms/con-20034608
