The Cool Down: Recognizing and Treating Heat-Related Illness
Dean Family Medicine doctor F. Bradford Meyers describes the symptoms of and treatments for heat-related illness
With the summer months comes heat, humidity and increased outdoor activity. These and other factors are associated with heat-related illness, conditions which we all must recognize. The body normally cools itself by sweating. This causes the efficient “evaporative cooling.” However, if the temperature and humidity are high, the air is still and the person is working hard or in fragile health, then the risk of heat-related illness increases.
At the mild end of the heat illness spectrum, the victim can be uncomfortable and fall ill. At the most severe end of the spectrum, life is in jeopardy.
Those at greatest risk of suffering heat-related illness are the elderly, the very young, those with heart disease, obesity, mental illness, poor circulation, sunburn, those un-acclimatized to the heat, and those using prescription drugs which limit sweating and decrease circulating blood volume.
Heat-related illness may be classified into three categories of increasing severity: heat cramps, heat exhaustion and heat stroke.
Overview: A mild form of heat-related illness. Must be recognized and treated at this level in order to prevent worsening severity.
Symptoms: Muscle pains or spasms, usually occurring in the abdomen, arms or legs. Associated with having performed strenuous activity, e.g. football practice, yard work, distance running.
What occurs? Sweating during vigorous activity leads to depletion of salt and moisture resulting in electrolyte disturbance and dehydration. Inadequate replacement of fluids and electrolytes may cause alteration in levels of sodium and potassium, leading to muscle cramping.
Treatment at home: Stop all activity. Rest quietly in a cool place. Drink fluids, typically, two glasses of water alternating with one glass of “sports drink.” Avoid strenuous physical exertion for a few hours after the cramps subside. Seek medical attention if the cramps do not subside within an hour.
Overview: A form of heat related illness that may occur over several days of exposure to high temperatures combined with inadequate replacement of fluids. Those most prone to this condition are the elderly, those on diuretic medications and those who must work or are exercising in a hot environment but who are not yet “acclimatized” to that hot environment. Those with obesity, poor conditioning, pregnancy, and any chronic illness or infirmity are at increased risk.
Symptoms: Heavy sweating, fatigue, headache, pale clammy skin, thirst, nausea and vomiting, weakness, mild body temperature elevations, tachycardia, dizziness (possibly with fainting), abdominal and extremity muscle cramping.
What occurs? Similar to heat cramps but at a more severe level. Exposure to high temperatures with inadequate intake of fluids leading to fluid and electrolyte depletion (such as that lost through sweating) which is inadequately replaced.
Treatment at home: Seek air conditioned environment if possible. Drink cool fluids (but not cold as these decrease gastric emptying). Increase heat dissipation by fanning, cool shower or bath. Focus on hydrating with water and “sports drink” rehydration solutions at ratio of two glasses of water to every one glass of sports drink. Prevention is important. Maintain hydration while working in hot environment. Regular cycles of rest are important for heat dissipation and to allow time to hydrate. Check on the elderly frequently during hot spells. Ensure they have access to fans, fluids, and air conditioning.
Overview: The most serious of the heat-related illnesses. The body is unable to control its temperature. The sweating mechanism fails and the body’s temperature rises rapidly to 106 degrees or higher within only 10 or 15 minutes. A life-threatening condition, this is a true medical emergency. Heat stroke can lead to death or permanent disability unless effectively treated very promptly.
Symptoms: Lack of sweating. Red, hot, dry skin. Rapid pulse. Throbbing headache, nausea, rapid rise of body temperature. Confusion may rapidly progress to loss of consciousness.
What occurs? Exposure to high heat and humidity can cause the individual to progress rapidly through heat cramps and heat exhaustion into heat stroke. Again, the elderly and infirm are most susceptible, but also those exercising strenuously in a hot environment when not properly acclimatized are at risk. Take, for example, the deaths by heat stroke in Arkansas a few years ago of members of a high school football team exercising vigorously in the heat.
Treatment at home: This is a medical emergency. Call 911. But treatment must start immediately. Cool the patient by all means available. Move to air conditioning or at least to shade. Apply ice packs to the armpits, the groin, and forehead. Place the victim in a cool shower, fan vigorously. Definitive treatment will occur in the ER, but what you do at home or in the field may save the victim's life.