Heading to the Cold? Here’s How to Cope
Some Southern Californians avoid freezing temperatures at nearly all costs. But snow in the Rockies and post-holiday air fare specials may inspire even the seriously cold-shy to venture onto the slopes or head to frigid climes to visit loved ones, if only for a few days. Once there, they may find that adapting to cold weather, especially after years of frost-free living, can be a challenge.
While physiologists dismiss the old saw that living in a warm climate thins the blood, they concede that the less time we spend in cold weather, the harder it becomes to adapt to it. Certain people do, they say, adapt more easily. But we can all improve our tolerance of freezing temperatures.
If you routinely travel between cold and warm regions, you adapt more easily than someone who visits cold climes infrequently, says Michael Sawka, chief of thermal and mountain medicine at the U.S. Army Research Institute of Environmental Medicine in Natick, Mass. “The more you are exposed to cold,” he says, “the better your body gets at handling it.”
When you are subjected to low temperatures, your blood vessels constrict to preserve heat. You shiver, which produces more body heat and boosts the metabolic rate. Your blood pressure may rise.
As we age, our ability to withstand the cold, or thermoregulation, tends to decline, says Lawrence Duffy, a professor of biochemistry at the University of Alaska, Fairbanks. In general, heavier people adapt to the cold more easily than thinner people because their surface-to-mass ratio keeps them warmer, Duffy says. And body fat “is a good insulator,” says John Castellani, a research physiologist with the U.S. Army Research Institute of Environmental Medicine. “Heat can’t move as well through the layer of fat sitting under the skin.”
Theoretically women have a slight insulation advantage, at least when unclothed, because of their generally higher percentage of body fat, Duffy says. But Castellani notes that women are usually smaller than men, and they often have less muscle mass to generate heat by shivering, so they are actually more likely than men to complain of feeling cold.
Some medications, including certain blood pressure-lowering drugs, can reduce tolerance to cold, at least in elderly patients. Those on medications should check product literature or ask a pharmacist if the drugs could affect their response to cold weather.
A few days or, preferably, weeks before a trip to a frigid locale, you can help acclimate yourself by taking a 30- to 60-minute walk in the chilly night air daily or every other day, Castellani says. Sawka notes that this regimen will help your body adapt by getting it accustomed to increasing blood flow to the hands more quickly, for instance. “To get the body in shape for cold, get a little chilly [before you go],” he says.
Once in the cold, dress for it. “Be sure all extremities are covered,” Duffy advises. Some experts say it’s a good idea to remember the acronym COLD--stay Clean, avoid Overheating, Layer and keep Dry. Soiled clothing can interfere with ventilation and keep moisture from wicking away from the skin. If you overheat, your clothes will become sweaty, and that makes them lose their insulating capacity. Layering clothes is particularly advised if you will be out in the cold for a prolonged period.
The layer next to the skin should ideally be silk or a synthetic such as polypropylene, Castellani says. The middle layer, which he says is most important, should be fleece. And the outer layer should be resistant to wind and water.
For cold-weather workouts, synthetics are probably better than cotton, according to researchers who compared the two and published their findings last month in the journal Medicine & Science in Sports & Exercise. The study evaluated subjects exercising indoors in warm rooms. The researchers found no difference in their skin temperatures or heart rate whether they wore cotton or synthetics. But cotton clothes retained more sweat, which in the cold would translate to a loss of insulation.
In extreme cold it’s also important to cover the face. “We had a visiting professor here who got frostbitten cheeks just walking around campus,” Duffy says. “It was minus 20 or minus 30; since then it’s warmed up to 20 above.”
Frostbite, the freezing of the skin or underlying tissues, can occur in only a few minutes, especially if there is a high wind-chill factor. Particularly susceptible are the hands, feet, ears and face. Redness usually develops first as the body gets blood flowing to the region, says Dr. Stephen Ross, chief of staff at Santa Monica-UCLA Medical Center. Then the skin may turn white and waxy or, in advanced stages, gray-blue or black.
There can be a fine line between simple numbness from the cold and frostbite, Ross says. If you feel numb and don’t warm the region, it can progress quickly to frostbite.
Medical help is advised even for mild frostbite. Until it is available, the affected areas should be warmed by rinsing them with water that is warm, not hot, to the touch of the person administering first aid. If no warm water is available, Ross says, try blowing on the skin. Then cover the area.
Another cold-weather risk is hypothermia, the potentially fatal lowering of the body’s core temperature to less than 95 degrees Fahrenheit. It is a risk especially to someone who isn’t used to the cold, Ross says.
A victim of hypothermia will experience chills, shaking and muscle aches. As the body temperature drops, mental confusion and slurred speech can occur. At this point it is essential to get to a warmer environment and get medical help, Ross advises. And it’s a mistake to think jumping around will warm you up, he adds; staying still will preserve more heat.
Drinking alcohol makes you feel warmer, but don’t be fooled. “Alcohol will make you lose more heat,” Ross says. “It dilates surface blood vessels,” allowing heat to escape.
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Healthy Traveler appears twice a month.
