Heat fatigue is one of several warning signs of heat-related stress and illness. It can precede a potentially life-threatening condition called a heatstroke. Working, exercising, or even simply spending too much time outdoors in very hot weather can lead to symptoms of heat fatigue. A person might start sweating profusely and develop a mild, widespread skin rash. Mental confusion and physical sluggishness progressively worsen if an individual does not seek a cooler environment and medical care. It is essential to recognize the early signs of heat fatigue to prevent severe health complications.
Body temperature is naturally regulated by processes that adjust blood circulation and excrete sweat. Under comfortable conditions, most people maintain body temperatures of about 98.6 degrees Fahrenheit (about 37 degrees Celsius). When hot weather and physical activity raise internal body temperature, sweating helps to cool the skin and the rate and amount of blood pumped throughout the body rises to compensate for exhausted organ systems. Extreme heat and activity can overwhelm regulating functions, resulting in body temperatures in excess of normal ranges and symptoms of heat fatigue.
In most cases, heat fatigue affects people who do not take the proper precautions when venturing outside in hot climates. Symptoms of heavy sweating, thirst, and tiredness can begin to arise within a matter of hours if a person does not take regular breaks and stay sufficiently hydrated. As more and more water is lost through sweat, a person can experiences muscle weakness, cramps, and hand tremors. Mental confusion, concentration problems, and poor decision making are characteristic of late-stage heat fatigue and can be signs of serious illness. If medical help is not sought, heat fatigue can lead to fainting, seizures, coma, and permanent damage to the heart and lungs.
A person who exhibits heat-related illness symptoms should be brought indoors immediately and given cold water to promote rehydration. When symptoms are minor and a person seems to recover quickly, a trip to the emergency room may not be necessary. Any further physical activity should be avoided for one or two days to make sure symptoms do not return. If fainting occurs or severe sluggishness is obvious, the problem must be addressed at an emergency room.
At the hospital, doctors can provide cooling blankets or ice packs and intravenous fluids. Breathing, heart rate, and concentration ability are carefully monitored and treated as necessary. Most people who receive immediate treatment are able to recover without lasting consequences, though they may need to make lifestyle changes and take extra precautions to prevent recurring episodes.