Area residents are getting a workout this winter when it comes to shoveling snow – and they should be careful, experts advise, because the combination of exertion and cold outdoor air can trigger a heart attack.

In snowy Rochester, N.Y., local hospitals can count on increased numbers of heart attack patients every winter, says Dr. Richard Pomerantz, chief of clinical cardiology at the University of Rochester Medical Center.

The danger is the impact cold temperatures can have on the blood vessels, which become smaller as temperatures drop. When coupled with physical activity, particularly shoveling heavy snow, this can increase the risk of clotting and heart attack.

People who don’t exercise regularly are especially at risk, Pomerantz said.

According to the folks at WebMD, it’s not clear why the incidence of heart attacks rises during the winter. Several factors may be involved, among them the body’s hormonal response to the wintertime decrease in daylight. Inflammation related to influenza and other viruses may play a role; overexertion in chilly outdoor air is also probably responsible.

Dress warmly and don’t overdo it, advises the American Heart Association.

The University of Rochester Medical Center has these additional tips:

- Know your risk factors. Heart disease can be hereditary, and the risk increases among people who are older, have high blood pressure, smoke, are overweight or don’t exercise.

- If you’re planning to shovel or spend time out in the cold and are aware you have risk factors, see your doctor for a physical before picking up a snow shovel – or ask someone else, such as a young neighbor, to shovel for you. Dress warmly and use a scarf or muffler to warm the air.

- Take frequent breaks while shoveling.

- Know that post-menopausal women are as susceptible as men to heart attacks.

- Know the symptoms of a heart attack – shortness of breath, sweating, nausea and chest pain. If you experience any of these, call 911 promptly. Be aware that heart attack symptoms are not always obvious, especially among women. For more information on the range of heart attack symptoms and how to recognize them, check out this podcast from the Mayo Clinic (a transcript is also available).