The high heat and humidity of the dog days of summer are uncomfortable for most of us, but for those with heart conditions, they can be dangerous -- even deadly. The American Association of Heart Failure Nurses (AAHFN) wants to remind individuals with cardiovascular disease of the risks of hot weather.

"While most of us know not to overexert during hot spells, you don't have to run a marathon to get become ill, especially those with heart conditions," said AAHFN President Robin Trupp. "It's easy to experience heat exhaustion or heat stroke doing simple, everyday activities, so it's important to be extra- careful during extreme heat."

AAHFN is a specialty organization dedicated to advancing nursing education, clinical practice and research to improve outcomes for patients with heart failure.

Heat and Your Heart

Our bodies are programmed to maintain a temperature of about 98.6 degrees Fahrenheit for optimum performance. If the body's temperature rises even a couple of degrees, it tries to cool itself down, mostly through perspiration and dilation of the blood vessels. The evaporating sweat cools the body and as a result of the larger blood vessel size, the heart beats faster and the blood pressure decreases.

"That increased heart rate and lower blood pressure can cause problems for those with heart disease," explained Trupp. "It might reach dangerous, even deadly, levels. As a rule, those with heart disease are sensitive to extremes in temperatures due to the challenges placed on the heart."

For those with heart failure, whose hearts may not be able to pump any harder to keep the body sufficiently cool and blood pressure high enough. As a result, the body can be become dangerously over-heated, and the result can be fatal.

Medications taken by many patients with heart disease can also cause problems in extreme heat, such as diuretics or water pills to reduce the fluid retention. During hot weather, diuretics may actually cause dehydration. However, patients should be warned against drinks large amounts of fluid, as recommended to the general public during heat spells, as this could add significant stress on heart and the cardiovascular system.

Beta-blockers, which are commonly prescribed, can prevent the heart from beating as rapidly as it needs to during hot weather, thereby limiting the body's ability to cool down.

Keep Your Cool

Overall, individuals with heart disease should follow the same guidelines as healthy individuals, but with an extra helping of precaution:

-- Stay inside during the hottest part of the day.

-- If your home isn't air conditioned, try to find someplace that is.

-- Limit your activity.

-- Wear loose-fitting, light clothing.

-- Stay hydrated and avoid caffeine and alcohol.

-- Have someone check in on you.

Recognizing Danger Signs

Knowing the signs of heat-related illness and knowing what to do can help save a life. The Centers for Disease Control and Prevention (CDC) identifies two types -- heat exhaustion and heat stroke.

Heat exhaustion is a milder heat-related illness that can develop after several days of exposure to high temperatures and an excessive loss of water and salt through sweat. According to the CDC, warning signs include:

-- Heavy sweating

-- Muscle cramps

-- Weakness

-- Dizziness

-- Headaches

-- Fainting

Anyone with heart problems or high blood pressure experiencing these symptoms should seek immediate medical attention.

Heat stroke, the most severe heat-related illness, occurs when the body is unable to regulate its temperature. Temperatures may rise to 106 degrees Fahrenheit or higher within 10 to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not provided.

The CDC lists these warning signs:

-- Extremely high body temperature (above 103 degrees Fahrenheit)

-- Red, hot, and dry skin (no sweating)

-- Rapid pulse

-- Throbbing headache

-- Dizziness

-- Nausea

-- Confusion

If you see any of these signs, have someone call for immediate medical assistance while you start cooling the victim by getting them to a shady area and immersing them in cool water. Do not give the person any fluids.

"Taking the proper precautions during hot weather can significantly reduce an individual's chances of suffering from heat-related illness this summer," said Trupp.

About AAHFN: The American Association of Heart Failure Nurses (AAHFN) is dedicated to advancing nursing education, clinical practice and research to improve outcomes for heart failure patients. For information visit http://www.aahfn.org

American Association of Heart Failure Nurses
http://www.aahfn.org