When the Heat Is On.

The hows and whys of preventing heat stress

My first "real" lesson in heat stress happened in a hospital when I was a victim of the flu. "Drink," medics ordered as they made their rounds. "Just drink." They made sure all water pitchers were filled. But I wasn't thirsty, and I felt bloated from all the liquids. So I cheated. Later I blacked out while using the bathroom, as my body temperature had risen to dangerous levels.

A nurse later explained my condition. "Your body is like a car," she said. "Without water it overheats." She explained that the body loses liquids and must be replenished. "The hotter you are, the more you must drink to cool yourself. If not, you could die."

The same principle also applies to healthy persons in hot and humid environments, especially when performing vigorous activities. Under these conditions, the body loses fluids and salts through perspiration as the body attempts to cool itself. There is a reduced flow of blood to the brain.

Eventually there can be discomfort, loss of concentration, or, in severe cases, stupor, loss of consciousness, or even death. News reports confirm the dangers every time a heat wave passes through the country. The bottom line is that heat stress is very serious. Even mild forms can easily escalate to something more severe and must be addressed immediately (see table below).

Types of heat injuries, their symptoms, and their treatment.

ILLNESS             SIGNS AND SYMPTOMS

Early heat stress   Mild dizziness, fainting, fatigue,
                    decreased concentration, confusion,
                    loss of coordination, thirst

Heat cramps         Painful spasms of arm, leg, or abdomen.
                    Heavy sweating and/or thirst

Heat exhaustion     Weakness, dizziness, fatigue,
                    impaired judgment. The victim's
                    skin is moist and clammy. There
                    maybe collapse. Thirst is
                    excessive. If victim is conscious,
                    pulse is rapid.

Heat stroke         Occurs suddenly. Headache, dizziness,
                    confusion, irrational behavior, coma.
                    Sweating may be slow or stop.
                    Rapid pulse and breathing. May have
                    convulsion, nausea, or incoherent
                    speech and aggressive behavior.
                    Its cause is sustained work in heat
                    and dehydration and reduced flow
                    of blood to the brain and other
                    vital organs. It risks damage to
                    all vital organs.

ILLNESS             TREATMENT

Early heat stress   Drink water, loosen or remove
                    clothing, rest in shade

Heat cramps         Loosen clothing, drink
                    fluids, rest

Heat exhaustion     Remove victim to a cool shaded
                    area as soon as possible.
                    Have him/her rest lying down.
                    If conscious, person should
                    drink as much water as possible.
                    Loosen or remove clothing and
                    splash cold water on the body.
                    If person loses consciousness,
                    get medical attention.

Heat stroke         Move to shaded area, remove
                    outer clothing. Use wet cloth
                    or pour water on victim. Fan.
                    Treat for shock if present
                    and when temperature is lowered.
                    Requires immediate medical
                    attention. If conscious, have
                    victim drink as much water as
                    possible.

Whom Does It Affect?

Everyone is susceptible. Some are more likely to succumb than others, however. Consider the following factors and pay appropriate attention if you or someone you know is particularly vulnerable.

* Age. Seniors are more likely to suffer heat injury.

* Acclimation. Newcomers to hot environments are more susceptible.

* Physical conditioning. Those in better physical condition can better withstand high temperatures. Marathon runners can run 26 miles in high temperatures because of their training. People not in condition, those with chronic or short-term ailments, and those on drugs/medication are more vulnerable.

A Simple Program of Prevention

You should enjoy summer and the outdoors. The following are the basic steps to prevention:

* Check environmental conditions. Some forget the heat when absorbed by another activity.

* Whether at work or play, watch your exertion level when hot. Schedule heavy work during cooler parts of the day. Shorten periods of activity or stop activity when extremely hot. Take longer and more frequent rest periods in the shade or in cool areas.

* Dress appropriately. Select the coolest possible clothing. Believe it or not, victims of heat stroke have been found wearing coats. Thin, woven fabrics that allow air movement through the material are best.

* Drink liquids to replace fluids lost from sweating. The U.S. Environmental Protection Agency's Guide to Heat Stress in Agriculture suggests adult agricultural workers dressed in normal clothing take at least a cup of water every 30 minutes when the temperature exceeds 90 [degrees] F. Dr. Jack Scarf, M.D., founder of the Honolulu Marathon Clinic, suggests runners take 8 ounces of liquid every 20 minutes. You may not run or do strenuous work, but you still need water. Drink, and drink often. "When you realize you're thirsty, it's too late," is Schaff's mantra at the clinic.

* Allow time to adjust. As in any conditioning program, do a little first and gradually work into shape.

* If indoors without air conditioning, be sure the area is well ventilated. G

Gerald Y. Kinro is a writer living in Kaneobe, Hawaii.