A heat emergency occurs when the heat-regulating mechanism in the body is not working correctly. The results of this malfunctioning can include high fever, collapse, convulsions, coma, and even death. A heat emergency generally occurs when the body is exposed to very high temperatures, generally exceeding 35- 40 degrees C (95-105 degrees F)
Symptoms can vary depending upon whether the condition is mild or severe. Early symptoms include: extreme sweatingincreased thirstnauseamuscle crampsfatigue and weaknesslight headedness and dizziness
Most of these symptoms are actually those of dehydration brought on by exposure to heat with inadequate fluid intake. This condition is termed "heat exhaustion".
As the problem grows worse, more severe symptoms can occur. These can include: contracted pupilsheadachepale, cool, moist skinmild confusionvomitingdecreased or absent urination
In the most severe form, a true emergency known as a heat stroke occurs. In this case, the body's temperature regulating mechanism has failed or is inadequate to cool the body to the proper temperature. The symptoms of a heat stroke may include: dry, hot, red skinfever greater than 100 degrees Fextreme confusionfast, shallow breathingweak, fast pulsedilated pupilsloss of consciousnessseizures
Heat emergencies are generally caused by: exercising for long periods of time or in very hot or hot and humid weatherwearing heavy clothes or many layers of clothing in hot weather
Factors that raise a person's risk of suffering a heat emergency include: very young (for example preschool age) or very old agealcohol usemedication use. Medications that can aggravate the problem include amphetamines, tranquilizers, antihistamines, and anticholinergics.heart disease such as coronary artery disease dehydration poor acclimation to hot climatemalfunctioning of sweat glands
A heat emergency can be a serious condition. People should take precautions against this problem in hot, humid weather. To prevent a heat emergency, a person should: avoid staying in the heat for long periods of timewear cool, loose clothing that is appropriate for the climatedrink more fluids than usual in order to stay well hydrateduse air conditioners, fans, and other means to keep cool
A healthcare professional will diagnosis a heat emergency by noting the person's symptoms, taking a medical history and performing a physical exam. A person will usually display some of the symptoms listed above.
The first step in treating a heat emergency is to have the person lie down in a cool place. The individual's feet should be elevated above the level of the heart. Next, cool wet clothing or water should be applied directly to the person's skin. Placing cold compresses on the person's head, groin, and armpits can speed cooling. These areas lose heat quickly.
A fan can also be used to help lower body temperature. Rubbing alcohol can cause serious health problems so it should not be used. Ideally, the individual's temperature should be measured rectally every 10 minutes. Fluid intake is very important.
The person should drink small sips of salted water (1 teaspoon salt per quart of water) or a salted drink such as Gatorade. If the affected person suffers a muscle cramp, the cramp can be relieved by squeezing the muscle firmly but gently until it relaxes. Massage can also help improve blood flow.
A person with heat stroke needs urgent medical attention. In a hospital setting, people with heat stroke are given intravenous fluids. Individuals may also require medication to stop seizures or raise dangerously low blood pressures. In severe cases, an the individual may need to be put on an artificial breathing machine, or ventilator, temporarily. Continued bed rest, IV fluids and observation may be required for several days.
Side effects of medication such as allergic reactions or stomach upset can occur. Specific side effects depend on the type of drugs used. Ventilators can rarely cause lung damage or infection.
After being treated for a heat emergency, a person may feel very tired for a few days. Most people recover without long-term problems. Severe cases can sometimes result in permanent problems such as brain damage.
Harrison's Principles of Internal Medicine, 1998, Fauci et al.
Emergency Medicine, 1998, Rosen et al.