Heat Disorders Health Article

Definition

Heat disorders are a group of physically related illnesses caused by prolonged exposure to hot temperatures, restricted fluid intake, or failure of temperature regulating mechanisms of the body. Disorders of heat exposure include heat cramps, heat exhaustion, and heat stroke (also called sunstroke).

Description

Hyperthermia is the general name given to heat-related illnesses. The two most common forms of hyperthermia are heat exhaustion and heat stroke, the latter of which is especially dangerous and requires immediate medical attention.

The thermal regulation centers of the brain help to maintain the body's internal temperature. Regardless of extreme weather conditions, the healthy human body keeps a steady temperature of approximately 98.6°F (37°C). In hot weather or during vigorous activity, the body perspires. As perspiration evaporates from the skin, the body is cooled. The thermal regulating centers in the brain help the body adapt to high temperatures by adjusting the amount of salts (electrolytes) in the perspiration. Electrolytes help the cells in body tissues maintain water balance. In hot weather, a healthy body will lose enough water to cool the body while creating the lowest level of electrolyte imbalance. If the body loses too much salt and fluid, symptoms of dehydration will occur.

Heat cramps

The care of heat cramps includes placing the child at rest in a cool environment, while giving cool water with a teaspoon of salt per quart, or a commercial sports drink (e.g. Gatorade). Usually, rest and liquids are all that is needed for the child to recover. Mild stretching and massaging of the muscles may be helpful once the condition improves. The child should not take salt tablets, because such a high concentration of salt may actually worsen the condition. When the cramps stop, the person usually can begin light activity again if there are no other signs of illness. The child needs to continue drinking fluids and should be watched carefully for further signs of heat-related illnesses.

Heat exhaustion

The child suffering from heat exhaustion should stop all physical activity and move immediately to a cool place out of the sun, preferably a cool, air-conditioned location. He or she should lay down with feet slightly elevated, remove or loosen clothing, and drink cold (but not iced), slightly salty water or a commercial sports drink. Rest and replacement of fluids and salt is usually all the treatment that is needed, and hospitalization is rarely required. Following rehydration, the child usually recovers rapidly.

Heat stroke

Simply moving the individual experiencing heat stroke to a cooler place is not enough to reverse internal overheating. Emergency medical assistance should be called immediately. While waiting for help to arrive, quick action to lower body temperature must take place.

Immediate treatment involves getting the child to a cool place, loosening clothing or undressing the person, and allowing air to circulate around the body. The next step is to wrap the child in wet towels or clothing, and place ice packs in areas with the greatest blood supply. These areas include the neck, under the arm and knees, and in the groin. Once the patient is under medical care, cooling treatments continue as appropriate. The child's body temperature is monitored constantly to guard against overcooling. Breathing and heart rate are monitored, and fluids and electrolytes are replaced intravenously. Anti-convulsant drugs may be given. After severe heat stroke, hospitalization may be necessary and bed rest is recommended for several days.

Demographics

Heat disorders are harmful to people of all ages, but their severity is greatest in young children and the elderly. Young children are at risk because, in relation to their weight, they have a large surface area of skin through which to lose water. In addition, until about age two, children's kidneys are not able to concentrate urine and preserve body fluids as efficiently as adult kidneys. The elderly also often have reduced kidney function or underlying diseases, or take medications that make them more vulnerable to dehydration. In healthy adults, heat stroke and heat exhaustion often affect athletes, firefighters, construction workers, factory workers, and anyone who exercises heavily and/or wears heavy clothing in hot, humid weather. Obese individuals and those with poor circulation or who take medications to reduce excess body fluids (diuretics) can be at risk when conditions are hot and humid.

When to call the doctor

The doctor should be called when the child shows any symptoms of heat exhaustion of if he or she has been exposed to heat and dehydrating conditions and has a body temperature of over 102°F (38.9°C). Emergency medical services should be called immediately if the individual has any symptoms of heat stroke or is having difficulty breathing.