Cold Weather InjuriesPennsylvania is experiencing winter wonderland a little early this year. Along with the recent snow we're experiencing very cold temperatures and cold weather increases the risk of cold weather injuries.
Humans are essentially a tropical species, but we're adaptable and we've developed ways to protect ourselves against environmental extremes. If you were going to Antarctica, chances are you'd take along protective gear. Yet people often fail to take necessary precautions against the elements when they're close to home, and that can lead to a variety of cold-related injuries, such as frostbite, hypothermia and chilblains-a milder form of frostbite caused by repetitive cold exposure and re-warming.
We generate body heat through movement and exercise. Outdoor activity helps heat to flow to the cold susceptible areas and protect them. Skiers are less at risk than hunters waiting in a tree stand. Small children, particularly babies, need more protection than their parents because they do not generate as much body heat and lose heat more easily. The elderly are more susceptible because they have less heat generating muscle mass than younger people.
Our skin regulates our body's temperature. That's why keeping our bodies covered up against the cold is so important. We lose heat through blood vessel dilatation and evaporation of sweat. In cold temperatures, our blood vessels constrict to shunt heat back to the organs. Unfortunately this takes heat away from our skin making it more susceptible to freezing. Extremities-fingers, toes, nose, and ears-are most susceptible. Diabetes, heart failure, alcoholism, cancer chemotherapy, narcotics, tranquilizers and some antidepressants and blood pressure medications affect skin circulation increasing the risk of cold injury.
Layers of dry clothing trap more heat than one thick layer. Hats reduce heat loss from the scalp which can shed up to ten percent of the body's heat. Gloves, scarves and ear muffs are also important accessories. Shoes and socks are usually enough for dry winters, but snow and slush can lead to wet feet and increase the risk of something called immersion foot or trench foot-a cold-induced injury that results from prolonged exposure of wet feet to cold but not necessarily freezing temperature. Hunters and others who will be walking through snow should have insulated, waterproof boots. If socks get sweaty, changing into dry socks is recommended, although wool socks will continue to insulate when wet. For prolonged outdoors activities, an inner layer of polypropylene or similar fiber helps trap heat and wick away perspiration.
Moisture on wet clothing also draws heat out of the body quickly and increases the risk of cold injury. Wet gloves or socks provide little protection. When skin is wet it doesn't take freezing temperatures to cause cold-related injuries.
As it chills, exposed skin first becomes painful due to reduced blood flow. The earliest sign of frostbite developing is numbness in the affected part. The colder the temperature, the faster this occurs. If sense of touch is reduced but still present no significant damage has occurred. When nothing can be felt in the affected area, frostbite has occurred in the skin. Fingers and toes get a "clumsy" feeling and do not move or bend. If medical attention and re-warming do not occur, frostbite damage can occur to the deeper muscle and bone.
If the fingers, nose, ears or toes burn or hurt, first try to protect them better. Put on gloves; use ear muffs or a scarf or get indoors. Once total loss of feeling and stiffness occurs, you have frostbite. Skin color will be pale. Thawing is painful and strong pain medication may be needed. It would be better to allow the part to remain frozen and seek medical attention rather than trying to thaw it yourself. If medical attention is not available soon, get to a warm place indoors and thaw the part.
The best way to thaw a frostbitten part is in warm water at about 100 degrees. Proper water temperature is important since further damage can occur if the frostbitten part is thawed too slowly or burned after being frozen. Rubbing the frozen part damages it further. Once thawed, protect the part from freezing again or the damage will be much worse. In severe freezes, the extent of damage may not be apparent for days or weeks.
Frostbite damage is like a bad burn. As with burns, you should consult your doctor if more than a trivial area was injured. Keep the injured area clean and watch for infection.
While frostbite results from freezing of the skin, hypothermia occurs when the body's inner temperature drops below 95 degrees. Heat flows out from the skin once the temperature drops below about 70 degrees so hypothermia can occur well above freezing.
Hypothermia is also treated by re-warming. If the person is conscious, put him or her in a warm room with layers of covering, such as, sweaters, blankets and so on. Provide warm beverages to increase internal temperature. If the person does not feel better in an hour, seek medical attention. If the person is confused or unconscious, cover him or her with blankets except for the nose and mouth and call 911. Although you may be tempted to handle it yourself, low body temperature can cause potentially fatal heart rhythm problems.
People with heart conditions should remember that exertion in cold weather is much more stressful than at moderate temperatures. Shoveling snow is as much work as running a seven minute mile.
Smoking and alcohol should be avoided. Dehydration and smoking reduce blood flow to the skin, further cooling it and making it susceptible to freezing. Smokers may need extra protection for frostbite susceptible parts. Don't buy into the old image of a St. Bernard carrying spirits to a snowy rescue. Alcohol increases blood flow to the skin which may cause a feeling of warmth, but it actually speeds heat loss.
If you can't move to Florida for the winter, remember these precautions and enjoy a safe and happy winter.