Cold Weather and Cardiac Arrest

Staying Safe In Freezing Temperatures

In our article on holiday stress and cardiac arrest, we touched on how the cold affects our circulatory system and the strain it can put on the heart of even seemingly healthy individuals.

With parts of the US seeing record low temperatures, and snow falling in places which haven’t seen snow in over 30 years, it seems worth revisiting the correlation specifically between cold weather and sudden cardiac arrest.

The Science 

Cold temperatures cause blood vessels to constrict, which means the heart has to pump harder to move oxygenated blood throughout the body. This raises blood pressure. For most people, the result is shortness of breath sooner while out in the cold, or those already suffering from a compromised cardiological system due to heart disease or some other condition, it can mean acute angina (chest pain), heart attack or even cardiac arrest.

A study in Sweden which spanned 16 years, and included over 280,000 cases of heart attack, showed a definite correlation between drops in temperature and hospital visits for heart issues. Since Sweden has universal healthcare and their hospital systems use a myocardial infarction registry, the data reporting was consistent. Additionally, meteorological data were available for comparison in 99% of the cases.

Keeping Yourself Safe

Dress Appropriately 

If you are going out to shovel snow or do some other kind of physical activity, dress in light, loose layers. This way you can shed layers as you work. Be sure to wear gloves, a hat, and boots, to keep extremities dry and warm. When clothing items which touch your skin become wet, you should change them to avoid frostbite, especially in subzero temperatures.

If you are not going to be working outside but will be outside for a while, wear a warm coat over warm clothing, a scarf which covers your mouth and nose to warm the air you breathe, and a hat which covers your ears. If you still feel cold and are shivering, get to someplace warm and add more layers before going back out.

The colder you are, the more your body has to work to warm itself up. Shivering or numbness in your fingers or toes are signs you are not warm enough.

Take It Easy

If you know your health is compromised, don’t exert yourself by engaging in strenuous outdoor activities in the cold before speaking with your doctor about your limitations. Shoveling snow, downhill and cross-country skiing, snowshoeing, or even building a snowman with your kids or grandkids can put a strain on your heart. If you are a typically healthy person who is engaging in these activities and suddenly find yourself short of breath, dizzy, nauseous, or feel a crushing pain in your chest, stop what you are doing and seek medical attention. You may be experiencing a heart attack, which can lead to cardiac arrest.

Stay Hydrated

Dehydration can lead to an additional strain on a heart already working overtime to keep blood moving through constricted vessels. Water also helps your muscles work more efficiently; in fact, muscle cramping is another sign of dehydration. If you feel dizzy or lightheaded while outside working or playing, anytime really, make sure you take a few moments to get some water into your system.

Avoid Alcoholic Beverages

Alcohol can “make you feel warm inside,” but it’s a false sense of warmth which may interfere with your body’s ability to recognize a lack of real warmth. Having a drink makes your blood vessels dilate and move warm blood closer to the surface of your skin. This is why people can think they feel warm and look “flush” after a few drinks. Unfortunately, it’s not actually raising your body’s temperature and the same effects the cold was having previously are still occurring but may seem less obvious the more alcohol is consumed.

The bottom line, really, is to pay attention to the signals your body sends you and take care of yourself to make sure you are around to enjoy the next snowfall or strange weather phenomenon in your area.

Related: Read about how to care for your AED when it gets cold outside and how to respond if someone has a heart attack (or stroke).