Heat disorders are a group of related illnesses caused by prolonged exposureto hot temperatures, restricted fluid intake, or failure of the body's temperature regulation mechanisms. Disorders related to heat exposure include heatcramps, heat exhaustion, and heat stroke (also called sunstroke). Heat strokeis especially dangerous and requires immediate medical attention.
As perspiration evaporates from the skin during hot weather, the body is cooled. Salt helps the cells retain water. If the body loses too much salt and fluids, the symptoms of dehydration can occur. In hot weather, a healthy body loses enough water to cool itself while creating the lowest level of chemicalimbalance. The healthy body maintains a temperature of approximately 98.6°F (37°C) regardless of surrounding conditions.
Heat cramps are the least severe of the heat-related illnesses. They are often the first signal that the body is having difficulty with increased temperature. Think of heat cramps as a warning sign to a potential heat-related emergency. They are painful muscle spasms caused by excessive loss of salts (electrolytes) due to heavy perspiration. They occur more often in the legs and abdomen than in other areas of the body. Individuals at higher risk are those working in extreme heat, elderly people, young children, people with health problems, and those who are unable to naturally and properly cool their bodies.Individuals with poor circulation and who take medications to reduce excess body fluids can be at risk when conditions are hot and humid.
The care of heat cramps includes placing the individual at rest in a cool environment, while giving cool water with a teaspoon of salt per quart, or a commercial sports drink. Usually rest and liquids are all that is needed. Mild stretching and massaging of the muscle area can follow once the condition improves. The individual should not take salt tablets, since this may actually worsen the condition. When the cramps stop, activity can usually be started again if there are no other signs of illness. The individual needs to continue drinking fluids and should be watched carefully for further signs.
Heat exhaustion, more serious and complex than heat cramps, often affects athletes, firefighters, construction workers, factory workers, and anyone who wears heavy clothing in hot humid weather. The skin may appear cool, moist, andpale. The individual may complain of headache and nausea witha feeling of overall weakness and exhaustion. Dizziness, faintness, and mental confusion are often present, as is rapid and weak pulse. Breathing becomes fast and shallow. Fluid loss reduces blood volume and lowers blood pressure. Yellow or orange urine often is a result of inadequate fluid intake, along with associated intense thirst.
Individuals suffering from heat exhaustion should stop all physical activityand move immediately to a cool place out of the sun, preferably an air-conditioned location. They should then lay down with feet slightly elevated, removeor loosen clothing, and drink cold (but not iced), slightly salty water or commercial sports drink. This is often all the treatment that is needed, and the person usually recovers within one or two days.
Heat exhaustion can develop rapidly into heat stroke, which can be life threatening. Because the percentage of victims dying from heat stroke is very high, immediate medical attention is critical when problems first begin. The body's temperature reaches a dangerous level, higher than 104°F (40°C) and as high as 106°F (41.1°C). Other symptoms include mental confusionwith possible combativeness and bizarre behavior, staggering, and faintness.The pulse becomes strong and rapid (160-180 beats per minute) with the skin taking on a dry and flushed appearance. There is often very little perspiration. The individual can quickly lose consciousness or have convulsions.
Simply moving the individual afflicted with heat stroke to a cooler place isnot enough to reverse the internal overheating. Emergency medical assistanceshould be called immediately. While waiting for help to arrive, quick actionto lower body temperature must take place. Clothes should be loosened or removed, allowing air to circulate around the body. Next, the individual should be wrapped in wet towels or clothing, with ice packs placed in areas with thegreatest blood supply. These areas include the neck, under the arm and knees,and in the groin. Once the patient is under medical care, cooling treatmentsmay continue as appropriate. Body temperature should be monitored constantlyto guard against overcooling. Breathing and heart rate should also be monitored closely, and a health professional may replace fluids and electrolytes intravenously. Anti-convulsant drugs may be given. After severe heat stroke, bed rest may be recommended for several days. Heat stroke is a very serious condition and its outcome depends upon general health and age. Due to thehigh internal temperature of heat stroke, permanent damage to internal organs is possible.
Because heat cramps, heat exhaustion, and heat stroke have a cascade effect on each other, the prevention of the onset of all heat disorders is similar. Avoid strenuous exercise when it is very hot. Individuals exposed to extreme heat conditions should drink plenty of fluids. It is important to wear light and loose-fitting clothing, and to consume water often without waiting until thirst develops. Eating lightly salted foods can help replace salts lost through perspiration. Ventilation in working areas can be improved by opening a window or using an electric fan. Sunblocks and sunscreens with a protection factor of 15 (SPF 15) can be very helpful in extreme direct sunlight.
Heat disorders are harmful to people of all ages, but their severity is likely to increase as people age. Heat cramps in a 16-year-old may be heat exhaustion in a 45-year-old and heat stroke in a 65-year-old.