Snow shoveling and skiing are typical activities engaged in by millions of people each winter.

However, cold weather coupled with strenuous activity can make the winter a dangerous time for anyone at risk for a heart attack — especially those recovering from a previous one.

People with previous heart attacks who are outdoors in cold weather should avoid sudden exertion, such as lifting a heavy shovel full of snow, according to the American Heart Association.

Even walking through heavy, wet snow or snowdrifts can strain a person’s heart.

In fact, every winter about 1,200 Americans die from a heart attack or a similar cardiac event during or after a big snowstorm, and shoveling snow is often the reason.

When people dig out from a storm first thing in the morning, stress hormone levels can rise and platelets in the blood become “stickier,” making heart attacks more likely to occur.

In addition, the cold air constricts blood vessels, increasing blood pressure and heart rate.

Another cold-weather factor is the flu, which affects about 20 percent to 26 percent of the U.S. population during the winter months.

In the elderly, vaccination against the flu has been shown to reduce the risk of hospitalization for cardiac disease by 19 percent.

Finally, the winter season is a time when many generally indulge themselves in excessive intake of food and alcohol at parties and other festive occasions.

Add to that increased physical and emotional stress levels, and the risk for a heart attack is even greater.

Everyone at risk for a heart attack — especially heart attack survivors — should know about precautions that can be taken to lower their risk factors during winter.

Some wintertime heart-healthy tips include:

• Ask your doctor if it is safe for you to shovel snow.

• Do not shovel snow for extended periods of time; shovel early and often — newly fallen snow is lighter than heavily packed or partly melted snow.

• Avoid smoking or drinking caffeine before shoveling snow.

• Replenish fluids, drink non-alcoholic fluids to prevent dehydration.

• In extremely cold temperatures, stay indoors.

• Get a flu shot early in the flu season.

• Eat a heart-healthy diet, and avoid over-eating during the holiday season.

• Stay active — but don’t overdo it. Pay attention to your body’s signals.