Heat exhaustion is a warning that the body is becoming overheated. Signs of heat exhaustion include heavy sweating, paleness, muscle cramps, fatigue, dizziness, headache, nausea or vomiting, and fainting. If the person does not get help, heat stroke may result. Heat stroke, also called sunstroke, is a medical emergency that is often fatal. It occurs when the body becomes unable to control its temperature by normal cooling mechanisms such as sweating. The body temperature may rise to 106 F or higher. Signs and symptoms of heat stroke include high body temperature, dry skin (no sweating), rapid pulse, headache, nausea, altered mental status, and unconsciousness. Seek immediate medical attention if someone has these symptoms.

Older adults can be at risk for heat-related illness at lower temperatures, particularly if the air is humid. High humidity hinders the evaporation of sweat from the body. If the temperature is 90 degrees, for instance, and the relative humidity is 70 percent, the air feels as though it’s 106 degrees. If you’re standing in full sun, it would feel as though the temperature were 121 degrees.

If you’re following a salt-restricted diet because of high blood pressure, you are at higher risk of developing heat-related illness. Don’t take salt pills without checking with your doctor. Older adults taking multiple medications also are at higher risk of heat-related illness. It’s important to drink extra fluids during hot weather, but ask your doctor if you need to watch how much you drink.

A person who is overweight has more difficulty regulating body temperature than someone of normal weight. An overweight person also retains more body heat.

Although fans and air conditioners work best, if you don't have either, you can still take steps to keep cool. Open windows at night to let cool air in. If possible, open windows on two sides of the house to allow a cross-flow of air. Keep blinds, drapes, or shades pulled during the hottest part of the day. Take a cool shower or bath.

Also check out shopping malls and movie theaters. If you don't have transportation, your local senior citizen center or agency on aging may be able to help.

Older adults often have poor circulation and inefficient sweat glands. Stick with lightweight, loose-fitting cotton clothing. Light-colored clothing also helps because it will reflect some of the sun’s heat. Also wear a wide-brimmed hat to keep the sun off your face.

People with heart disease or emphysema have a more difficult time during a smog alert.

Symptoms of heat fatigue include cool, moist skin and a weak pulse. Symptoms of heat exhaustion include profuse sweating, giddiness and cold, clammy skin; the pulse is normal or increased.

If possible, also have the person lie down and rest. Offer the person cool water or fruit juice; avoid beverages that contain caffeine or alcohol. Sponging off with cool water will also ease symptoms.