With severely cold weather gripping more than half of our nation, it's important for us to be prepared and keep in mind the risks associated with cold weather spells.
What is Frostbite?
Frostbite (congelatio in medical terminology) is a medical condition where localized damage is caused to the skin and other tissues due to prolonged exposure to extreme cold. Frostbite is most likely to happen on body parts that are exposed and farthest from the heart, although it can affect any part of the body.
What causes Frostbite?
When exposed to cold temperatures for a prolonged period of time, your body works to preserve core body temperature by reducing the flow of blood to extremities (e.g. fingers, toes, nose, ears, etc). During this process, the blood vessels near your skin begin to constrict and blood flow can reach dangerously low levels (which can lead to the eventual freezing and death of tissue).
Frostbite is measured in four stages
The first phase of frostbite only affects the top layers of the skin and is commonly referred to as ‘frostnip'. During onset, one might experience itching and some pain followed by numbness and the development of white, red, and yellow patches on the skin. Frostnip does not usually cause permanent damaged because it only affects the skin's top layers. Although, long-term sensitivity to both heat and cold can sometimes happen.
During this phase, the skin may freeze and harden, but the deep tissues below the skin are not affected (deep tissues remain soft and normal). Blisters may appear 1–2 days after exposure, but will heal with proper aid and care. As always, consult your physician concerning proper care strategies.
Third & Fourth Degrees
If the tissues below the skin freeze, deep frostbite occurs. During these phases, the muscles, tendons, blood vessels, and nerves below the skin freeze and the tissue may die. The skin is hard, feels waxy, and use of the area is temporarily lost (in severe cases, use of the area is permanently lost). Deep frostbite can sometimes be accompanied by areas of purplish blood-filled blisters on the skin which eventually turn black. Nerve damage in the area can result in a loss of feeling. In extreme cases, frostbitten areas may need to be amputated because the area becomes infected with gangrene (the death of some body tissue due to the lack of blood supply).
Symptoms of Frostbite
Common warning signs include a progressive numbness and a loss of sensitivity to touch. The affected area will also tingle or feel as if it's burning. As the condition worsens, the pain begins to fade or eventually disappear.
The skin also changes color when exposed to extreme cold. It blanches, then may appear red, and finally white-purple if allowed to freeze.
Many people say the affected part of the body feels "wooden," and it may appear to have a wooden texture.
In mild cases, full recovery can be expected with early treatment. Severe cases of frostbite can result in infection, or gangrene.
When you first notice signs of frostbite, come out of the cold immediately and rewarm the affected area.
To thaw frostbitten skin, you can immerse the affected body part for an hour or more in warm water (do not use water that is overly hot!). Warm water will cause the blood vessels to dilate and circulation to return to the area. If you do not have access to warm water, stick the frozen body part under an armpit or between the thighs to warm gradually. As the tissue rethaws, the skin may turn red and swelling may develop. Dark blisters may also appear on the skin and continue to form over the ensuing week(s) as new skin develops.
Rewarming the affected tissue can be an intensely painful procedure. To dull the pain, you can take recommended dosage of ibuprofen, aspirin, or acetaminophen.
Do not smoke or chew tobacco. Nicotine constricts the blood vessels, reduces blood flow to chilled areas, and delays the healing process.
Avoid rubbing, massaging, shaking, or otherwise applying physical force to frostbitten tissues in an effort to get blood flowing back to the affected area. This causes friction and will destroy the already damaged skin and underlying tissue, as well as increase the risk of infection.
When the skin has thawed and rewarming is complete, cover the damaged skin with bandages and warm clothing. Contact your doctor or go to an emergency room as soon as possible.
If there is any chance of refreezing a thawed body part, do not rewarm it in the first place! Freezing, rewarming, and freezing of the skin and tissues causes much more damage than being frozen once.
Prevention of Frostbite
Before going outside in extremely cold temperatures, dress warmly, wear dry clothing, and stay out of the wind. Wear a face mask for extra protection. Wear heavy mittens instead of gloves in freezing cold weather – when the fingers are together in a mitten, their collective body heat keeps the hand warmer.
Keep an Eye on Children
Children playing outside should be watched carefully to make sure that they do not lose or remove mittens or head-coverings.
When Pumping Gas
Be extremely careful when pumping gas into your car if the temperature is below freezing. Gasoline on exposed skin evaporates very quickly, lowers the temperature of the skin, and makes it more susceptible to frostbite.
When you exercise in below-freezing temperatures, wear layers of clothing. The more layers you wear, the better insulated you are. The innermost garment must be nonabsorbent and loosely woven.
Don't Ignore the Signs
Go inside, if possible, when you feel too cold. Remember that fatigue, lack of oxygen in high elevations, and consumption of alcohol may cause you to disregard discomfort and cold.
Avoid Smoking & Alcohol
Avoid smoking or drinking before venturing out into extreme cold. Tobacco decreases circulation by constricting blood vessels, and alcohol interferes with the body's ability to regulate temperature.
CH2M HILL AlumniConnect | February 1, 2011