Anytime skin is exposed to very cold temperatures, there is a risk of frostbite. Most commonly fingers, toes, nose, ears, cheeks and chin are affected when exposed to cold temperatures.
While cold weather is the most common type of exposure, skin that comes in direct contact with ice, frozen metal or very cold liquids may also succumb to frostbite.
However, even skin covered by gloves or other clothing is susceptible to frostbite when exposed to temperatures below 32 degrees (Fahrenheit). Risk of frostbite increases in temperatures below 5 degrees (Fahrenheit). Wind chills of -16.6 (Fahrenheit) can lead to frostbite on exposed skin in less than 30 minutes.
When skin becomes very cold and red, frostbite may occur. If exposure to the cold continues, the skin will become numb, hard and pale. These symptoms indicate that skin and the underlying tissues are freezing. Because skin becomes numb with frostbite, the victim may not realize it’s happening.
Less severe forms of frostbite include frostnip and superficial frostbite. Frostnip doesn’t result in permanent skin damage and can be treated with basic first-aid, including rewarming the affected skin. As the skin is warmed, tingling and pain may occur.
Superficial frostbite causes skin to redden and turn pale or white. If the skin begins to feel warm, it could indicate serious skin involvement. Treating this level of frostbite with rewarming may cause the skin to appear mottled. Stinging, burning and swelling may occur. Within 12 to 36 hours of rewarming, a fluid-filled blister may occur.
Severe frostbite, as it progresses, affects all layers of the skin, including underlying tissues. When this level of frostbite occurs, skin turns white or bluish-gray. Numbness may occur along with all sensation of cold, pain or discomfort in the affected area. Muscles and/or joints in the affected area may no longer function. With rewarming, large blisters can occur within 24 to 48 hours of rewarming. As the tissue in the affected area dies, the skin will turn black and hard.
Conditions that can lead to frostbite include wearing clothing unsuitable for protecting skin from cold, windy, wet weather conditions; exposure to cold and wind for an extended period of time; and touching elements such as ice, cold packs or frozen metal.
Factors that further increase risk of frostbite include medical conditions such as dehydration, excessive sweating, exhaustion, diabetes and poor blood flow to limbs. These conditions may hinder the ability to feel or respond to cold. Alcohol or drug abuse and smoking may also be contributing factors
Conditions that inhibit sound judgment and ability to respond to overexposure to cold include fear, panic or mental illness; previous frostbite or cold injury; high altitudes, which reduce oxygen supply to skin.
Infants or aging adults are particularly susceptible to frostbite because they may have difficulty producing and retaining adequate body heat.
Signs and symptoms of frostbite include cold skin accompanied by a tingling sensation; numbness; skin color that is red, white, bluish-white or grayish-yellow; hard or waxy-looking skin; clumsiness due to joint and muscle stiffness; and blistering that occurs after rewarming, a common condition in severe frostbite cases.
Medical assistance is advised if increased pain, swelling, redness or discharge occurs in an area where frostbite occurred. Other signs that medical attention is necessary include fever and/or new or unexplained symptoms.
In the interim, before medical help arrives, appropriate self-care measures include protecting the area from further exposure to cold, avoiding walking on frostbitten feet and reducing pain with ibuprofen.
Once frostbite occurs, other complications may arise, such as increased sensitivity to cold and risk of recurring frostbite, long-term numbness in the affected area, excessive sweating, skin color changes, loss of or changes in fingernails/toenails, joint stiffness or frostbite arthritis, infection, tetanus and decay and death of tissue due to interruption of blood flow to the frostbitten area. This condition — gangrene — could lead to amputation.
Hypothermia, which may be indicated by intense shivering, slurred speech, drowsiness and loss of coordination, is another potential complication to watch out for.
Staying warm and safe in cold weather conditions can be accomplished with some simple steps.
Dress appropriately for weather conditions. This includes use of several layers of loose, warm clothing. When air is trapped between layers of clothing, it acts as insulation again cold temperatures. Undergarments that wick moisture away from the skin help skin stay dry. Windproof and waterproof outer garments protect against wind, snow and rain.
If clothing becomes wet — especially gloves, hats and socks — change them as soon as possible.
Wear a hat or headband that fully covers the ears. The most protective headwear materials include woolen or windproof fabric. Wear mittens rather than gloves because mittens better protect the hands. A thin pair of glove liners made of wicking fabric (such as polypropylene) may be worn under a pair of heavier gloves or mittens.
Socks and sock liners should be made of wicking materials and fit well. Hand and foot warmers may also be effective in protecting against cold. Avoid socks or foot warmers that cause boots to fit tightly as this restricts blood flow.
Eat well-balanced meals and stay hydrated prior to spending time outdoors. These practices assist in staying warm. Never drink alcohol before spending time in cold weather. Alcoholic beverages expedite cause the loss of body heat.