Heat and congestive heart failure: a dangerous combination

Handling heat can be difficult for people with heart disease, especially heat and congestive heart failure. When it's hot and humid outside, the heart has to work harder to cool the body. If you have congestive heart failure, high temperatures can make it even more challenging — with potentially dangerous consequences. When the temperature rises, taking a few simple precautions can help you stay safe.

What is congestive heart failure?

Having congestive heart failure doesn't mean your heart is on the verge of shutting down. It means your heart is not pumping at full strength and is unable to deliver all the blood your body needs.

Congestive heart failure can cause a variety of symptoms, including shortness of breath, fatigue, and difficulty breathing. There's no cure for congestive heart failure, so the goal of treatment is to control symptoms and boost quality of life with exercise, diet, and medication.

If congestive heart failure gets worse, you may need an implantable device to help your heart pump correctly or surgery to repair a defect. For severe congestive heart failure that hasn't responded to treatment, a heart transplant may be necessary.

How heat affects congestive heart failure

High heat and humidity can be challenging for people with congestive heart failure and other heart conditions because they can disrupt the body's natural cooling processes. Two things can happen:

• Extra blood goes to the skin. When it's hot, your skin needs more blood to send heat out of your body and into the air. Your heart has to work harder to supply this extra blood.
• Sweating takes a lot out of you. Sweating expels heat but at a cost. When you sweat, you lose valuable minerals, and the body makes hormones to try to reduce these losses. This can tax your heart.

Tips for recognizing and responding to heat illness

How hot is too hot? When the temperature reaches 70 degrees Fahrenheit with a humidity level of at least 70%, your heart has to work harder to keep you cool. The threat to your heart increases as the temperature and humidity rise.

When it's hot and humid outside, avoid outdoor activity until it's cooler. Exposure to high heat and humidity with congestive heart failure can cause you to overheat.

You may develop symptoms such as excessive sweating, muscle cramps, rapid pulse, clammy skin, nausea, headache, dizziness, or weakness. These are signs of a heat illness called heat exhaustion.

Move into an air-conditioned space as quickly as possible, place cool towels or washcloths on your body, and sip water. Seek medical attention right away if you're vomiting, your symptoms worsen, or they don't go away in an hour.

If you stop sweating, have red skin, difficulty breathing, or your body temperature is 103 degrees or higher, seek medical attention immediately. You may be experiencing a dangerous condition called heatstroke.

What you can do to stay safe in the heat

Look out for your heart and your health by following these heat safety tips:

• Choose outdoor exercise times carefully. Don't exercise or perform chores outside during the hottest part of the day. Instead, save outdoor activities for the early morning or evening, and exercise in an air-conditioned location during the muggiest hours.
• Dress lightly. Wear light-colored, airy clothing that doesn't trap heat or sweat close to your body.
• Stay hydrated. Drink plenty of water when heat and humidity are high. If your primary care provider or cardiologist gives instructions on daily fluid intake, be sure to follow them, as fluid retention can be an issue for people with congestive heart failure. Don't drink alcohol or caffeinated beverages, which can fuel dehydration.

Need an expert's help to manage congestive heart failure? Schedule a consultation with a heart and vascular specialist at the Reid Health Heart & Vascular Center.