If you love getting out in the summer sun, you know that sometimes, you have to be careful. The heat and humidity can bring added danger—especially if you have heart disease. The heart attack risk calculator doesn’t account for it, but if you understand why heat and humidity are hard on your heart, you’ll be better prepared to protect yourself when the temperature rises.
According to the Environmental Protection Agency, the combination of heat and heart disease can be a deadly one. In fact, their researchers say about 25 percent of heat-related deaths are tied to the convergence of heat, humidity and heart disease. Older adults are even more at risk. People age 65 and older are more more likely to die from heat-related cardiovascular disease than the general population. African-Americans also have higher-than-average rates.
Most healthy people tolerate extreme changes in the weather without missing a beat. But if your heart is damaged, it may not be so simple. Let’s look at why heat and humidity can be hard on your heart, especially if you have heart disease, and what you can do to decrease your risk.
Heat and Humidity: A Deadly Combination
When your body temperature goes up, so does your risk of heat-related illness, or even death, especially if you have heart disease.
University at Albany researchers recently discovered that temperature had a bigger impact on cardiovascular disease death when combined with high humidity. It intensifies the temperature effects on those with existing cardiac health problems. The reasons why this happens may vary.
Harvard University researchers say people with damaged or weakened hearts have a much harder time handling the heat and may develop heat stroke. The same goes for older adults whose bodies don’t respond to stress as well as they used to.
Why Heat is Hard on a Damaged Heart
Some of the ways their researchers say heart disease or heart damage is made worse in heat and humidity include:
- If you suffer a heart attack, the resulting damage can keep your heart from pumping enough blood to allow your body to cool properly.
- Blood flow to the skin may also be limited by a hardening of your arteries brought on by cholesterol.
- Medications can make it harder for your body to regulate heat. Beta blockers will slow your heartbeat and limit your heart’s ability to circulate blood fast enough for effective heat exchange. Diuretics (water pills) increase urine output, which can leave you dehydrated. Some antidepressants and antihistamines can block sweating.
- A stroke, Parkinson’s disease, Alzheimer’s disease, diabetes and other conditions can dull the brain’s response to dehydration, so you may not be aware you’re thirsty.
Heat, Humidity and Heart Failure
If you’re living with heart failure, you should be particularly careful in hot, humid weather. That’s because your heart is having trouble pumping blood—it is not pumping efficiently. The heat and humidity will cause your heart to work harder. It can be compounded even further by the sodium and potassium you’re losing in your sweat. The combination of increased blood flow to the skin and dehydration may drop blood pressure enough to cause dizziness or falls.
Recognize the Signs of Heat Exhaustion
If you do have heart disease, try to avoid going outside on extremely hot and humid days. Talk to your doctor about what temperatures should be most concerning to you. You should also remember the signs and symptoms of heat exhaustion:
- Cool, moist skin
- Dizziness or becoming light-headed
- Nausea and vomiting
- Dark urine
If you experience these symptoms, move to a cooler place, stop exercising or working, and cool down immediately. You can do this by using cool wet cloths or compresses and fanning yourself. You may need to seek medical attention.
If you do have heart disease and must go out in the heat, as a precaution, do not go alone. Always have someone close by who can help you if you start to feel sick.
It’s also important to remember the symptoms of heat stroke: If you or someone you’re with is experiencing some of the signs, call 911 right away. They include:
- Fever (temperature above 104° F)
- Irrational behavior
- Extreme confusion
- Dry, hot and red skin
- Rapid, shallow breathing
- Rapid, weak pulse
One simple thing you can do to decrease your risk is to drink water—even when you’re not thirsty. Keeping your body hydrated in the heat is a good defense and can help protect your heart.
You can also download our free Summer Survival Guide. You’ll uncover six tips you can use to keep you and your family safe—all summer long.