Hyperthermia: too hot for your health

The National Institutes of Health
From NIH Research Matters (NIH)

July 5, 2012  

Hot summer weather can pose special health risks to older adults. The National Institute on Aging (NIA), part of the National Institutes of Health, has some advice for helping older people avoid heat-related illnesses, known as hyperthermia.

Hyperthermia is an abnormally high body temperature caused by a failure of the heat-regulating mechanisms of the body to deal with the heat coming from the environment. Heat fatigue, heat syncope (sudden dizziness after prolonged exposure to the heat), heat cramps, heat exhaustion and heat stroke are commonly known forms of hyperthermia. Risk for these conditions can increase with the combination of outside temperature, general health and individual lifestyle.

Lifestyle factors can include not drinking enough fluids, living in housing without air conditioning, lack of mobility and access to transportation, overdressing, visiting overcrowded places and not understanding how to respond to hot weather conditions. Older people, particularly those with chronic medical conditions, should stay indoors on hot and humid days, especially when an air pollution alert is in effect. People without air conditioners should go to places that do have air conditioning, such as senior centers, shopping malls, movie theaters and libraries. Cooling centers, which may be set up by local public health agencies, religious groups and social service organizations in many communities, are another option.

Health-related factors, some especially common among older people, that may increase risk of hyperthermia include:

• Being dehydrated.
• Age-related changes to the skin such as impaired blood circulation and inefficient sweat glands.
• Heart, lung and kidney diseases, as well as any illness that causes general weakness or fever.
• High blood pressure or other conditions that require changes in diet. For example, people on salt-restricted diets may be at increased risk. However, salt pills should not be used without first consulting a doctor.
• Reduced sweating, caused by medications such as diuretics, sedatives, tranquilizers and certain heart and blood pressure drugs.
• Taking several drugs for various conditions. It is important, however, to continue to take prescribed medication and discuss possible problems with a physician.
• Being substantially overweight or underweight.
• Drinking alcoholic beverages.

Heat stroke is a life-threatening form of hyperthermia. It occurs when the body is overwhelmed by heat and unable to control its temperature. Heat stroke occurs when someone's body temperature increases significantly (generally above 104 degrees Fahrenheit) and has symptoms such as mental status changes (like confusion or combativeness), strong rapid pulse, lack of sweating, dry flushed skin, faintness, staggering, or coma. Seek immediate emergency medical attention for a person with any of these symptoms, especially an older adult.

If you suspect that someone is suffering from a heat-related illness:

• Get the person out of the heat and into a shady, air-conditioned or other cool place. Urge them to lie down.
• If you suspect heat stroke, call 911.
• Encourage the individual to shower, bathe or sponge off with cool water.
• Apply a cold, wet cloth to the wrists, neck, armpits, and/or groin. These are places where blood passes close to the surface of the skin, and the cold cloths can help cool the blood.
• If the person can swallow safely, offer fluids such as water, fruit and vegetable juices, but avoid alcohol and caffeine.

The Low Income Home Energy Assistance Program (LIHEAP) within the Administration for Children and Families in the U.S. Department of Health and Human Services helps eligible households pay for home cooling and heating costs. People interested in applying for assistance should contact their local or state LIHEAP agency.

For a free copy of the NIA's AgePage on hyperthermia in English or in Spanish, contact the NIA Information Center at 1-800-222-2225 or go to http://www.nia.nih.gov/health/publication/hyperthermia-too-hot-your-health orhttp://www.nia.nih.gov/espanol/publicaciones/hipertermia (Spanish).

The NIA leads the federal effort supporting and conducting research on aging and the medical, social and behavioral issues of older people. For more information on research and aging, go to http://www.nia.nih.gov/.