Although winter is a beautiful time of the year, with it comes low temperatures, shorter daylight hours and snow. Cold weather can wreak havoc with your heart’s health. Many of you aren’t even aware that you’re at risk until you have a heart attack, so it’s very important to know your risk factors.

Your risk of heart disease increases if you’re older, a smoker, overweight, have high blood pressure, don’t exercise enough or have a stress-filled life. And heart problems can also be hereditary. If you’re at risk, you must be especially careful during the winter months. Why?

• Colder temperatures cause your blood vessels to get smaller, which reduces the flow of blood and oxygen supply to your heart.
• Your blood becomes thicker when temperatures drop, and this can cause an increase in the risk of clotting.
• Cold weather can lead to an increase in blood pressure, which puts more stress on your heart.
• If you’re not used to exercising, your risk of a heart attack during winter weather may increase from overexertion. For example, you shovel snow when you’re only accustomed to lifting the TV remote.
• If you don’t know the dangers of being outdoors in cold weather, you could suffer from hypothermia—an abnormally low body temperature. Most deaths from this condition are caused by heart failure.
• During the winter time, “there is a change in the ratio of daylight to dark hours, which changes the hormonal balance, and the hormones involved such as cortisol, can lower the threshold for a cardiovascular event,” said Stephen P. Glasser, M.D., from the University of Alabama at Birmingham, School of Medicine in a health report.

And now that you know your risk factors for heart disease, and the extra strain cold weather can put on your heart, you can be better prepared to protect your heart’s health during these harsh winter months.