Feeling the burn - Special Report - exercise safety and heat exhaustion prevention

An epidemic that claimed the lives of more than 700 people, in a little over two weeks, sounds like an unfortunate incident in an underdeveloped nation. Yet, this epidemic actually occurred in Chicago, Illinois, during a relentless heat wave that gripped portions of the United States during the summer of 1995.

Heat-related illnesses range from the most benign, heat cramps, (causing painful muscle spasms) to the most severe, heatstroke (often a deadly condition). Exertional heatstroke is known to occur when exercising during extreme heat. However, extreme temperatures are not necessarily the sole factor responsible for causing heat-related illnesses. Each syndrome can be induced by numerous risk factors increasing the effects of hot weather. In fact, illness can and does occur in mild or moderate climates.

Top Five Ways to Avoid a Heat-Related Illness

Severe heat-related illnesses and their harmful effects usually occur because warning symptoms are ignored. When interviewing victims, "they often tell me they thought they were drinking enough [fluids] and were adequately prepared for warmer weather. To clinically note their level of dehydration and, on occasion, their high body temperature, these patients have obviously underestimated their physiologic requirements and the effects of the environment," says Valerie Wallace, an emergency room nurse at Memorial Pembroke Hospital in Pembroke Pines, Florida. If you notice a client appearing ill, have him/her stop all activity and seek shade (optimally an air-conditioned room). Warn your clients that continuing to exercise through early warning signs may impair their ability to realize he/she is becoming seriously ill.

1. Time of Day

For those insisting on outdoor activity, particularly in the hotter or more humid months, encourage scheduling workouts earlier or later in the day. This minimizes exposure to the hotter, harsher afternoon sunlight and temperatures. Remind clients to exercise in the shade, when possible, and to take a buddy along in case illness sets in. Tell them to reserve those all-out "busters" for cooler times or an indoor, air-conditioned facility.

2. Physical Condition

One does not need to be exposed to warm temperatures to become overheated. Heat is a metabolic by-product of exercise. Simply stated, "the body's temperature will increase when heat is produced at a greater rate than eliminated," says Dr. Sindee Weiss, an intensivist at North Shore University Hospital, in Long Island, New York, and a clinical instructor in Medicine at New York University School of Medicine. A healthy body will produce heat when under exertion (almost any form of physical exercise). Less fit clients will generally expend more energy exercising than those who are well-conditioned.

Encourage clients to see their physician prior to starting an exercise regimen. Thereafter, always observe their level of conditioning. Remember, conditioning is dynamic and can change within minutes. If a rapid change occurs, it is usually a downward trend. Try to set regimens within the parameters of your clients' capabilities. Obesity and older age are also well-known risk factors for heatstroke. Nevertheless, limiting the controllable risk factors evens the field considerably. Remember, heat cramps and exhaustion show no age bias--they strike well-conditioned athletes and non-athletes of all ages.

3. Fluid Intake

Adequate hydration plays a key role in preventing heat-related illnesses. You cannot overemphasize the importance of fluid intake. Inform clients that a water/fluid bottle is an essential piece of workout equipment. They should be drinking water or a sports beverage before feeling thirsty or fatigued. Be sure to caution those who are hypervigilant about fluids to take in salts with water, which in large quantities also causes diuresis.

4. Medications and Medical Conditions

Many conditions, prescriptions and over-the-counter (OTC) medications can intensify the effects of a heat-related illness or mask the body's ability to signal danger (e.g., keeping the heart rate low, impairing sweating). It is best to consult a pharmacist or physician about any medications being taken, no matter how briefly.

Medical Conditions

* Cardiovascular diseases

* Diabetes

* Certain neurologic conditions

* Chronic skin conditions (can impede sweat production).

* Diarrhea (even brief diarrhea illnesses can disrupt the body's salt and fluid balance, thus resulting in fainting spells and harmful falls).

* Alcoholism and use of illicit substances.

Medications

* Cardiovascular agents (including diabetes and anti-hypertensive medications)

* Antihistamines/decongestants

* Antispasmodics

* Psychotropics

Others

Over-the-counter sleeping and motion sickness agents typically contain antihistamines, while most OTC nasal sprays and appetite suppressants contain decongestants or similar agents. Caffeine is another stimulant to avoid. Alcohol and use of illicit substances have been associated with numerous heat-related deaths. Moreover, alcoholic beverages have a diuretic effect hastening dehydration and act as a sedative, thus impairing awareness of an impending heat-related illness. Wallace also notes, "In the emergency room, I frequently encounter patients taking dietary supplements or herbal products. There is a noticeable lack of awareness of the impact these products can have on heat-related illnesses or interactions with prescribed medications."

5. Clothing

Particularly on bright, sunny days, wearing light-colored, loose clothing is recommended. Cotton or synthetic breathable garments, such as GoreTex[R] or Supplex[R], help promote dryness and allow body heat to escape. Hats or caps will prevent the sun from heating the blood vessels lining the scalp, but remember to occasionally remove the cap to let heat escape. Cool, wet towels on the scalp, across the neck, wrists or along the armpits also aid in cooling the body.

Recognizing Heat-related Illnesses

Weakness, dizziness, headache, muscle cramps, nausea and vomiting are common symptoms of heat-related illnesses. Heat cramp victims usually sweat profusely, although they do not run temperatures. Conversely, heatstroke victims feel extremely warm and are stricken with high body temperatures resulting in brain or other organ injury. Although many victims perspire profusely, it is not uncommon for sweating to be absent. Mental changes start with fatigue and can progress to unconsciousness.

What to Do

Immediately take the person out of direct sunlight immediately to a cooler, shady spot--optimally an air-conditioned room--and call for medical help. Have the person lie down and slightly elevate his/her feet. If the person is not vomiting or having difficulty breathing, replace lost fluids with cool beverages. Then, loosen or remove his/her clothing and apply cool, wet towels.

Gerard R. Barber, RPh, MPh, resides in Valrico, Florida, and writes about health-related issues. He has trained at the Centers for Disease Control and Prevention and conducted clinical research and award-winning studies in the field of surgical wound infections at New York's Memorial Sloan-Kettering Cancer Center. He is an assistant clinical professor of pharmacy at the University of Florida and is published among newspapers, consumer magazines and professional journals including the American Journal of Medicine, Archives of Surgery and the New England Journal of Medicine. He can be reached via e-mail at GerardB@LRMC.com.

COPYRIGHT 2001 Aerobics and Fitness Association of America
COPYRIGHT 2001 Gale Group