by Lawrence R. Schiff, MD, FACEP

Regular physical activity does your heart good. But exercising outdoors in cold weather puts an extra strain on your heart—boosting heart rate and blood pressure. That’s because when the temperature dips, your body requires extra oxygen simply to keep warm. Add sudden, intense exertion—like running, skiing, or shoveling snow—and your heart rate and blood pressure can skyrocket.

None of this is a problem if you’re healthy. But if you have a family or personal history of heart disease—or if you have been inactive—check with your doctor before beginning an outdoor exercise program during the winter months. 

People with asthma should also seek medical advice before exercising outdoors in cold weather, because inhaling very cold air can trigger an asthma attack. Wrapping a scarf loosely around the face may warm the air enough to make breathing comfortable.

Here are some other tips for safe cold-weather exercise:

• ŸKeep moving to keep warm.
• ŸDrink plenty of fluids; dehydration disturbs the body’s ability to regulate temperature.
• ŸWear a hat and dress in layers to hold in body heat.
• ŸWear mittens instead of gloves; they keep your fingers warmer.
• ŸWear shoes with good traction to avoid slipping on snow or patches of ice.
• ŸTo avoid overheating, wear one less of layer of clothing than you would if you were outside but not exercising.
• ŸAvoid alcohol before heading outdoors.

Alcohol consumption and physical activity in cold weather can increase the odds of hyperthermia.  Despite the fact that alcohol can provide an initial feeling of warmth, this is due to the expansion of blood vessels in the skin.  Alcohol actually causes heat to be drawn away from the body’s vital organs.

 Hypothermia occurs when more heat escapes from your body than your body can produce.  Severe hypothermia can lead to death.  The cause of hypothermia usually is extended exposure to cold temperatures or a cool, damp environment. Other contributing causes include inadequate clothing and neglecting to adequately cover your extremities, particularly your head — a disproportionate amount of heat is lost through your head.

Your normal core body temperature is usually right around 98.6 F.  In hypothermia, your body fails to maintain a normal temperature. An internal body temperature of 95 F or lower, signals hypothermia.

Hypothermia usually occurs gradually. Often, people aren't aware that they need help, much less medical attention.  The signs and symptoms of the person suffering from exposure to the cold are the strongest indicators of hypothermia. Seek immediate medical care for anyone who has been exposed to cold air or water and is shivering, appears disoriented, shows a lack of coordination, has cold and pale skin, appears tired, and is slurring speech. Try to keep the person warm and dry, preferably indoors or at least out of the wind, until help arrives.

This information is provided by Lawrence R. Schiff, MD, Chairman of Emergency Medicine at Eastern Long Island Hospital.