Dear Savvy Senior: I’ve read that people with heart problems need to be extra careful during the winter months because heart attacks are much more common. Why is this? — Cautious Senior

Dear Cautious: Everyone knows winter is cold and flu season, but many don’t know that it’s also the prime season for heart attacks, too, especially if you already have heart disease or have suffered a previous heart attack. Here’s what you should know, along with some tips to help you protect yourself.

In the U.S. the risk of having a heart attack during the winter months is twice as high as it is during the summertime. Why? There are a number of factors, and they’re not all linked to cold weather. Even people who live in warm climates have an increased risk. Here are the areas you need to pay extra attention to this winter.

>> Cold temperatures: When a person gets cold, the body responds by constricting the blood vessels to help the body maintain heat. This causes blood pressure to go up and makes the heart work harder. Cold temperatures can also increase levels of certain proteins that can thicken the blood and increase the risk for blood clots. So, stay warm this winter, and when you do have to go outside, make sure you bundle up in layers with gloves and a hat, and place a scarf over your mouth and nose to warm up the air before you breathe it in.

>> Snow shoveling: Studies have shown that heart attack rates jump dramatically in the first few days after a major snowstorm, usually a result of snow shoveling. Shoveling snow is a strenuous activity that raises blood pressure and stresses the heart. Combine those factors with the cold temperatures and the risks for heart attack surges. If your sidewalk or driveway needs shoveling this winter, hire a kid from the neighborhood to do it for you, or use a snow blower. Or, if you must shovel, push rather than lift the snow as much as possible, stay warm and take frequent breaks.

>> New Year’s resolutions: Every Jan. 1, millions of people join gyms or start exercise programs as part of their New Year’s resolution to get in shape, and many overexert themselves too soon. If you’re starting a new exercise program this winter, take the time to talk to your doctor about what types and how much exercise may be appropriate for you.

>> Winter weight gain: People tend to eat and drink more and gain more weight during the holiday season and winter months, all of which are hard on the heart and risky for someone with heart disease. So, keep a watchful eye on your diet this winter and avoid bingeing on fatty foods and alcohol.

>> Shorter days: Less daylight in the winter months can cause many people to develop “seasonal affective disorder,” or SAD, a wintertime depression that can stress the heart. Studies have also looked at heart attack patients and found they usually have lower levels of vitamin D (which comes from sunlight) than people with healthy hearts. To boost your vitamin D this winter, consider taking a supplement that contains between 1,000 and 2,000 international units (IU) per day.

>> Flu season: Studies show that people who get flu shots have a lower heart attack risk. It’s known that the inflammatory reaction set off by a flu infection can increase blood clotting, which can lead to heart attacks in vulnerable people. So, if you haven’t already done so this year, get a flu shot for protection. And, if you’ve never been vaccinated for pneumococcal pneumonia, you should consider getting these two shots (given 12 months apart), too.

Jim Miller is a contributor to NBC-TV’s “Today” program and author of “The Savvy Senior.” Send your questions to Savvy Senior, P.O. Box 5443, Norman, OK 73070; or visit savvysenior.org.