While "Old Man Winter" can't keep some enthusiasts from exercising outside — whether they be jogging, skiing, skating, etc. — exercising outside in cold weather can be hazardous for asthma sufferers, according Dr. Abraham Sanders, a pulmonologist at the New York Weill Cornell Medical Center.

"It's crucial that all asthmatics know about possible triggers," Sanders said. "For active men and women, that means being aware of potential dangers of cold weather exercise."

Sanders offers the following tips when exercising in winter:

• Always cover your mouth and nose with a scarf to warm the air before you inhale.

• Warm up with stretching and light activity before exercising, shoveling or beginning more strenuous physical activities. Be sure to cool down as well.

• Take all medications as prescribed, even if you feel fine.

• Use common sense — if it's too cold or icy, go inside for mall walking or another activity.

• When exercising indoors, make sure the room is well humidified and ventilated.

• Dress in layers — layering clothing helps maintain body heat.

• Drink plenty of fluids. Your body needs fluids during cold weather, too. Try carrying a water bottle.

• If you have been sedentary or have health problems, check with your doctor before starting any exercise program.