Being in a cold environment causes our bodies to make certain physiological adjustments to preserve our core body temperatures. These normal adjustments can present a challenge to people with heart disease.
Cold temperatures cause:
- Your heart rate to increase.
- Your blood pressure to increase.
- Your heart to work substantially harder.
- An increase in the propensity for blood clotting.
All of the above factors can lead to acute cardiac problems in somebody with heart disease. While everyone needs to take precautions when they are in a cold environment, precautions are especially important if you have a heart problem.
People who particularly are at risk of a heart problem during cold outdoor activities include:
- Those with known heart disease, such as coronary artery disease or heart failure
- Those with multiple risk factors for heart problems, including high blood pressure, high cholesterol, diabetes and smoking
- Those who lead a sedentary lifestyle
Here are things people with heart conditions should consider during extreme cold and weather conditions:
Limit your cold exposure. Limit the time you spend out in the cold, and if you go out, dress warmly, in several layers, cover your head and hands, and wear warm socks and shoes.
Don’t exert yourself too much. Shoveling snow can easily trigger a cardiac emergency, including angina, heart attack, and worsening of heart failure. 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. 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.
Don’t let yourself become overheated. Dressing warmly then engaging in physical activity can lead to overheating. Overheating, in turn, causes blood vessels to suddenly dilate — which can lead to hypotension (low blood pressure) in a person with heart disease. 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.
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. The flu is potentially dangerous in anyone with heart disease. Get a flu shot. And if you feel yourself developing symptoms of the flu, talk to your doctor before medicating yourself.
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.
People who don’t take certain precautions can suffer accidental hypothermia, which means the body temperature has fallen below about 95 degrees Fahrenheit. It occurs when your body can’t produce enough energy to keep the internal body temperature warm enough. It can kill you.
Symptoms of hypothermia people should be aware of:
- Lack of coordination
- Mental confusion
- Slowed reactions
Who is most at risk?
- Children and the elderly are at special risk because they may have limited ability to communicate or impaired mobility.
- Elderly people may also have lower subcutaneous fat and a diminished ability to sense temperatures, so they can suffer hypothermia without knowing they’re in danger.
In addition to cold temperatures, high winds, snow and rain also can steal body heat. Wind is especially dangerous because it removes the layer of heated air from around your body. At 30 degrees Fahrenheit in a 30-mile per hour wind, the cooling effect is equal to 15 degrees Fahrenheit. Similarly, dampness causes the body to lose heat faster than it would at the same temperature in drier conditions.
To keep warm, wear layers of clothing. This traps air between layers, forming a protective insulation. Also, wear a hat or head scarf. Heat can be lost through your head. And ears are especially prone to frostbite. Keep your hands and feet warm, too, as they tend to lose heat rapidly.
Tips for making snow removal safer:
- Consult a doctor if you have a medical concern or question or if you are experiencing symptoms of a medical condition (such as heart disease or diabetes), prior to exercising in cold weather – especially if this is a substantial increase over your usual level of activity.
- Avoid shoveling immediately after you awaken as most heart attacks occur early in the morning when blood is more prone to clotting. Wait for at least 30 minutes and warm up.
- Do not eat a heavy meal before shoveling. Blood gets diverted from the heart to the stomach.
- Warm up your muscles before starting by walking for a few minutes or marching in place.
- Do not drink coffee or smoke for at least one hour before or one hour after shoveling or during breaks. These are stimulants and elevate your blood pressure and heart rate.
- Don’t drink alcoholic beverages before or immediately after shoveling. Alcohol may increase a person’s sensation of warmth and may cause them to underestimate the extra strain their body is under in the cold.
- Give yourself a break. Take frequent rest breaks during shoveling so you don’t over stress your heart. Pay attention to how your body feels during those breaks.
- Use a small shovel. Shovel many small loads instead of fewer heavy ones.
- Learn the heart attack warning signs and listen to your body, but remember this: Even if you’re not sure it’s a heart attack, have it checked out (tell a doctor about your symptoms). Minutes matter! Fast action can save lives — maybe your own. Don’t wait to call 9-1-1
- Be aware of the dangers of hypothermia. To prevent hypothermia, dress in layers of warm clothing, which traps air between layers forming a protective insulation. Wear a hat because much of your body’s heat can be lost through your head.
- Learn CPR. Effective bystander CPR, provided immediately after sudden cardiac arrest, can double or triple a victim’s chance of survival. Hands-only CPR makes it easier than ever to save a life. If an adult suddenly collapses, call 9-1-1 and begin pushing hard and fast in the middle of the victim’s chest until help arrives.
Muhammad Akhtar, MD, is a cardiologist with Ascension Medical Group at Weston. For more information, call 715-393-3860 or visit ascension.org/wisconsin.