Though the evening temperatures have lowered, daytime temperatures soar. The danger of heat-related emergencies hasn't disappeared. One-hundred-degree weather isn't always needed for such emergencies. With the hunting seasons near and still warm weather, some will expose themselves to heat stress.

A sudden increase in temperature can be serious because it can place a dangerous strain on the heart and blood vessels before the body can acclimate itself.Heat stress, which can lead to heat exhaustion, heart failure and strokes, and heat strokes, may well be a life-threatening problem for the elderly. Death tolls because of overheating are highest among people over 65 years of age.

The elderly are more vulnerable to heat stress than younger people because they do not adjust as well to heat. They perspire less. They are also more likely to have health problems requiring medicines that work against the body's natural defenses to adjust to heat.

For example, diuretics (often prescribed for high blood pressure, a common disease of the elderly) prevent the body from storing fluids and restrict the opening of blood vessels near the skin's surface. Certain tranquilizers and drugs used to treat Parkinson's disease interfere with perspiring. These and other chronic conditions (such as circulatory problems, diabetes, a previous stroke, overweight and a weak or damaged heart) often upset normal body responses.

Warning signs

Early symptoms - feeling hot, uncomfortable and listless - are mild and usually pose no threat unless they persist. However, because the serious signs of heat stress listed below are usually preceded by the milder ones, it is important that medical attention be obtained if any of the following are experienced:

- Dizziness

- Rapid heartbeat

- Diarrhea

- Nausea

- Cramps

- Throbbing headache

- Dry skin (no sweating)

- Chest pain

- Mental changes

- Breathing problems

- Vomiting

These symptoms can also signal other major problems, such as heart failure. Again, if any of these are experienced, call for medical consultation.

Keeping cool

The best advice for avoiding heat stress is to keep as cool as possible. These may help avoid problems:

- Air conditioning can provide life-saving relief from heat stress, especially for those with heart disease. If air conditioning is unavailable, spend as much time as possible in cool shopping malls, senior centers, libraries, movie theaters or in the coolest room in your home.

- Fans can draw cool air into a home at night or help circulate indoor air during the day.

- Cool baths or showers provide relief from heat since water removes extra body heat 25 times faster than cool air. Placing wet towels or ice bags on the body is also helpful.

- Loose-fitting, lightweight, light-colored clothing is more comfortable in hot weather. Hats and umbrellas protect the head and neck when outdoors.

- Don't wait until thirsty to drink water.

- Watch salt use. Don't take salt tablets without a doctor's permission.

- Avoid alcohol. It acts as a diuretic, resulting in fast water loss. It also makes a person less aware of the danger signs of heat stress.

- Those living alone should be checked by a relative or neighbor regularly.