Dear Dr Jeff: Last weekend I froze my toes teleskiing at Sugarloaf. They're still kind of numb and tingly. Did they get frostbitten? What can I do about it now? G.G.
Dear G.G.: Hopefully your toes only got frost-nipped, a less damaging form of cold injury than frostbite.
Cold injuries come in different forms and degrees. Chilblains, or pernio, are the mildest form. They're characterized by localized itching, swelling, redness and sometimes blisters in the cold-exposed areas.
Moving up the severity scale, there's frostnip, which causes affected skin to turn white and soft, and leaves you with that sensation of pins and needles. No blistering occurs, and no permanent damage results. Symptoms usually resolve spontaneously within one to three weeks.
Even with frostnip, though, you need to keep your toes warm until they've fully recovered. Remember too that all cold injuries, including frostnip, will leave you more vulnerable to future cold exposure.
Superficial frostbite causes your skin to feel numb, waxy and frozen. Ice crystals form in the outer layers of your skin, but the underlying tissues remain pliant and pink. Pressing down on the area with a fingertip will leave an indentation, and blistering occurs frequently.
Deep frostbite can be very serious, resulting in limb amputation and even death. Water in body tissues and within cellular spaces freezes and crystallizes, causing sometimes-irreversible damage to those tissues and cells. When blood vessels are involved, they can clot off and cut off the supply of oxygen to the affected area, causing gangrene.
Serious infections, including tetanus, often follow. Deeply frostbitten tissues are described as wooden-feeling, hard and without sensation. The overlying skin may be white, grayish-yellow or grayish-blue in color, and there is usually no blistering involved. Prompt and proper medical attention is critical, and can often save even deeply frozen limbs.
While hands and feet are affected most frequently, frostbite can also involve your cheeks, nose, ears and even corneas. As frostbite develops, you may develop excessive sweating or joint pains. Other warning signs include slurred speech and disorientation.
The risk of frostbite is proportional to both the degree of cold and the length of exposure. Wind chill can greatly worsen the impact of both. Other risk factors include exposure to water or dampness, prolonged immobilization, high altitude, fatigue, previous cold injury, nicotine use (constricts blood vessels), and altered mental status (from head trauma, psychiatric illness, alcohol or recreational drug use). Individuals from warmer climates are at greater risk for frostbite. Medical conditions like malnutrition, infection, arthritis, diabetes, thyroid disease and vascular disease also increase one's susceptibility to cold injury.
If you ever think you have frostbite, even superficial, you should seek medical attention immediately. If you're out in the field, whatever else you do, don't allow the affected area to thaw and then refreeze.
The damage will be compounded many times over. It is considered far better to walk on frozen feet to a permanent shelter, even risking tissue chipping and fracture, than it is to attempt rewarming, if any danger of refreezing exists.
Replace wet clothing with dry, soft clothing if possible. Rewarm the affected area as soon as safely possible, using warm water or warmed, wet towels. Avoid dry heat to thaw the injured area, and don't massage the area with your hands or rub it with snow.
Drink warm fluids if available, and avoid alcohol (which will increase your blood flow to other unaffected areas). If blisters have formed, leave them intact. Cover them loosely with a clean cloth or bandage, and keep the affected area or limb elevated.
For most of us, frostbite is a completely preventable injury. Proper clothing for winter weather should insulate from the cold, allow perspiration to evaporate, and provide protection from wind, rain and snow.
Make sure your clothing and footwear are not too tight. Wear waterproof skin moisturizer on exposed areas, or better still, cover them up. Use hand-warmers and toe-warmers. Increase your fluid and caloric intake during cold weather, and limit your use of alcohol, tobacco and mind-altering substances.
At high altitude, moderate your activity in very cold weather, so as to minimize the work and the heat loss of breathing. You might also consider using supplemental oxygen.
If you have to go out in extreme cold, try to head out with a buddy, and check each other frequently for signs of frostbite.
Be well! It's cold up at the Loaf! Be prepared! And stay warm!
Jeff Benson, M.D.
Dudley Coe Health Center