SUNDAY, Aug. 10 (HealthDay News) -- Because aging affects the body's ability to respond to summer heat, older adults are particularly at risk for heat-related illnesses such as heat stroke, heat fatigue, heat cramps and heat exhaustion, according to the U.S. National Institute on Aging (NIA).

Factors that may increase the risk of heat-related illnesses include:

• Age-related changes to the skin such as poor 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 dietary changes. For example, people on salt-restricted diets may be at increased risk for heat-related illnesses. However, salt pills shouldn't be used without first consulting a doctor.
• The ability to sweat can be impaired by medications such as diuretics, sedatives, tranquilizers and by certain heart and blood pressure drugs.
• Taking several drugs for various conditions. However, it's important to continue taking prescribed medications and discuss possible problems with a doctor.
• Being substantially overweight or underweight.
• Drinking alcoholic beverages.
• Being dehydrated.

The risk of heat-related illnesses can also be increased by lifestyle factors such as hot living quarters, lack of transportation, overdressing, visiting overcrowded places, and not understanding weather conditions.

Older adults, particularly those at special risk, should stay indoors on hot and humid days, especially when there is an air pollution alert in effect, the NIA recommends. Those without fans or air conditioners should go to air-conditioned places such as shopping malls, movie theaters, libraries or cooling centers operated by social service agencies and senior citizen centers. If possible, older adults should get family or friends to give them rides to air-conditioned locations.

If you suspect someone is suffering from a heat-related illness, the NIA recommends the following:

• Get the person out of the sun and into an air-conditioned or other cool place. Have them lie down and rest.
• Offer fluids such as water, fruit and vegetable juice. Don't offer alcohol or caffeinated beverages.
• Encourage the person to shower, bathe or sponge off with cool water.
• Apply a cold, wet cloth to the wrists and/or neck, places where arterial blood passes close to the surface and can be cooled by the cold cloths.

More information

The U.S. Centers for Disease Control and Prevention has more about heat illness and the elderly.