Heat Related Illness

What is it?

Heat illnesses occur when the body produces more heat than it loses. Humans must maintain a core body temperature of between 36.8 and 37.5 degrees Celsius. When the body is exposed to a hot humid environment sodium and water in the body are lost to the environment in the form of sweat. In addition, blood is redirected to the skin to aid in heat dissipation. As the humidity (moisture content in the air) increases, sweat does not evaporate as readily. Sweat evaporation stops entirely when the relative humidity reaches about 90%. If exposure to heat and humidity continues, the core body temperature may continue to rise leading to various illnesses.

Types of Heat Illness

There are three major heat-related illnesses that people should be aware of: heat stress, heat exhaustion and heat stroke.

Heat Stress

The first sign of heat stress is often mental confusion or a decrease in the ability to think and reason clearly. Unfortunately, these symptoms are very subtle and the affected person usually does not notice the change. Other signs can include nausea, dizziness, thirst and weakness. As water is lost from the body through sweat faster than it is being replaced cramps involving the extremities and abdominal muscles often occur.

Heat Exhaustion

This is a more serious illness and is caused by excessive sweating and severe loss of water and salt. Excessive sweating causes dehydration which strains the circulatory system. Symptoms include moist, clammy skin which appears ashen and gray, enlarged pupils, confusion, vomiting, weakness and in some cases unconsciousness. Without proper treatment heat exhaustion can result in physical collapse.

Heat Stroke

This is the most severe of the three illnesses. It is caused by a breakdown in the body’s temperature regulating system resulting in a rapid rise in the body’s temperature. When the temperature rises too high brain tissue can be permanently damaged. Symptoms include dry, red-hot skin, loss of consciousness, convulsions, rapid pulse and breathing.

What To Do If Someone Has Symptoms

• Move the person to a cool place.

• Lie the person down with the feet elevated.

• Remove unnecessary clothing.

• Provide liquids in small sips; water is best.

• Place a cool cloth on the forehead or back of neck.

• Moisten the person with cool water.

• Fan the patient.

• In the case of heat stroke call an ambulance immediately.

Preventing Heat Related Illness

To avoid heat-related health problems, follow these tips during the summer:

• Wear loose clothing that will allow perspiration to evaporate.

• Depending on the activity, drink about one quart of water per hour.

• Avoid alcohol and caffeinated beverages.

• Avoid drinking heavily sweetened beverages.

• Schedule sports, or high-energy activities, for early morning or early evening.

• Pace activities to allow the body to rest.