By Richard N. Fogoros, MD 

 Medically reviewed by Anthony Pearson, MD

If you have heart disease, staying healthy during cold weather presents special challenges.

For those with coronary artery disease (CAD), cold temperatures can trigger episodes of cardiac ischemia (when the heart muscle doesn't get enough oxygen). This can cause episodes of angina, when the heart doesn't receive enough blood flow, or even heart attacks.1

For people who have heart failure, a rapid drop in environmental temperature can cause a sudden worsening of symptoms. It can also lead to an increased risk of hospitalization and even an increased risk of death.2

That means when you have heart disease, the onset of cold temperatures requires special precautions. Fortunately, these precautions generally fall into the category of common sense.

This article discusses how cold temperatures affect your heart. It also lists five precautions to take in the cold weather when you have heart disease.

How the Cold Affects Your Heart

A cold environment causes your body to make certain adjustments to preserve your core body temperature. These normal adjustments can present a challenge if you have heart disease.

Cold temperatures cause your blood vessels to constrict or get more narrow. This helps minimize heat loss from your blood to regulate your body's normal internal temperature.3

When your blood vessels constrict, your blood pressure increases. Your heart has to work harder to pump blood through the constricted blood vessels in the body.

If you have a healthy cardiovascular system, this blood vessel constriction shouldn't cause problems. However, if you have coronary artery disease (plaque in your arteries), it may lead to a blockage in the artery, which could cause a heart attack.4

Recap

When it's cold outside, your blood vessels constrict to minimize heat loss. Your heart works harder to pump blood through your blood vessels. If you have heart disease, it may put you at greater risk for a heart attack.

Cold Weather Precautions for Heart Disease

Everyone needs to take precautions when they are in a cold environment. However, precautions are especially important if you have a heart problem. Follow these five tips to stay healthy in the cold weather:

1. Limit your cold exposure. Limit the time you spend outside when it's cold. If you go out, dress warmly in several layers. Cover your head and hands, and wear warm socks and shoes.

2. Don’t exert yourself too much. As any paramedic knows, shoveling snow can trigger a cardiac emergency for a person with heart disease. It can lead to angina, heart attacks, heart failure, and sudden death.5 Ambulance crews make sure their vehicles’ gas tanks are full (and their defibrillators operative) if a snowstorm is on the way.
   
   If you are going to shovel snow, do it when there’s an inch or less on the ground. Use a smaller shovel, and push (rather than lift) the snow. Never shovel wet, heavy, or deep snow. Many cardiologists insist that their patients never shovel snow at all.
   
   Snow shoveling, of course, is not the only way to overexert yourself during the cold weather. Walking more rapidly than usual is common when the wind is blowing in your face. Just being out in the cold pushes us to exert ourselves.

3. Don’t let yourself become overheated. Dressing warmly and then engaging in physical activity can lead to overheating. Overheating causes blood vessels to suddenly dilate or widen—which can lead to hypotension (low blood pressure) if you have heart disease.6
   
   If you are out in the cold and you find yourself sweating, you are overheated. If you have heart disease, consider this sweating to be a danger sign. Stop what you are doing and get indoors.

4. Get a flu shot. Winter also raises your chances of getting the flu due to low humidity brought on by cold weather and indoor heating.7 The flu is potentially dangerous in anyone with heart disease.8
   
   Get a flu shot. And if you feel yourself developing symptoms of the flu, talk to your healthcare provider before medicating yourself.

5. Don't drink alcohol. Avoid alcohol before going outdoors. It expands blood vessels in the skin, making you feel warmer while actually drawing heat away from your vital organs.9

Summary

Cold weather can increase your risk of heart attack if you have heart disease. The cold temperature causes your blood vessels to constrict. This increases your blood pressure and makes your heart work harder to pump blood.

If you have heart disease, take precautions in cold temperatures. Stay inside when possible and dress warmly when you have to go out. Follow your healthcare provider's advice about shoveling snow. They may suggest that you avoid it completely.

Don't overexert yourself in the cold weather and avoid drinking alcohol. Also, remember to get your flu shot, since the flu is dangerous when you have heart disease.

9 Sources

Fares A. Winter cardiovascular diseases phenomenon. N Am J Med Sci. 2013;5(4):266. doi:10.4103/1947-2714.110430

Vanasse A, Talbot D, Chebana F, et al. Effects of climate and fine particulate matter on hospitalizations and deaths for heart failure in elderly: A population-based cohort study. Environ Int. 2017;106:257–266. doi:10.1016/j.envint.2017.06.001

Wigley FM. Patient education: Raynaud phenomenon. UpToDate.

Mohammad M, Koul S, Rylance R et al. Association of weather with day-to-day incidence of myocardial infarction. JAMA Cardiol. 2018;3(11):1081. doi:10.1001/jamacardio.2018.3466

Nichols RB, McIntyre WF, Chan S, et al. Snow-shoveling and the risk of acute coronary syndrome. Clin Res Cardiol. 2012;101:11-15. doi:10.1007/s00392-011-0356-6

Harvard Medical School: Harvard Health Publishing. Avoiding winter heart attacks.

Sooryanarain H, Elankumaran S. Environmental role in influenza virus outbreaks. Annu Rev Anim Biosci. 2015;3:347–373. doi:10.1146/annurev-animal-022114-111017

Modin D, Jørgensen ME, Gislason G, et al. Influenza vaccine in heart failure. Circulation. 2019;139(5):575–586. doi:10.1161/CIRCULATIONAHA.118.036788

Maufrais C, Charriere N, Montani J. Cardiovascular and cutaneous responses to the combination of alcohol and soft drinks: The way to orthostatic intolerance?. Front Physiol. 2017;8. doi:10.3389/fphys.2017.00860

By Richard N. Fogoros, MD
Richard N. Fogoros, MD, is a retired professor of medicine and board-certified in internal medicine, clinical cardiology, and clinical electrophysiology.