Under these circumstances, the body temperature rises and may cause illness. There are several common heat-related illnesses. Some are more severe than others. Heat rash, or prickly heat , occurs when blocked sweat glands become inflamed. This painful rash reduces the body's ability to sweat and to tolerate heat.
Heat cramps are painful spasms of the muscles.
The muscles used in doing the work are most susceptible. The spasms are caused by the failure of the body to replace its lost body salts and usually occur after heavy sweating. Heat exhaustion results when the body loses large amounts of fluid by sweating during work in hot environments. The skin becomes cool and clammy. Symptoms include profuse sweating, weakness, dizziness, nausea, and headaches.