If heat gain exceeds the ability of the body to lost heat, then body temperature increases above normal levels, a condition called hyperthermia. Hyperthermia can result from exposure to hot environments, exercise, fever, and anesthesia.
Individuals suffering from heat exhaustion have a wet, cool skin because of the heavy sweating. They usually feel weak, dizzy, and nauseated. Treatment includes reducing heat gain by moving to a cooler environment, reducing heat production by muscles by ceasing activity, and restoring blood volume by drinking fluids.
On the other hand, if heat loss exceeds the ability of the body to produce the heat, body temperature decreases below normal levels. Hypothermia is a decrease in body temperature to 35 degrees C (95 Degree F) or below. Hypothermia usually results from prolonged exposure to cold environments. At first, normal negative-feedback mechanisms maintain body temperature. Heat loss is decreased by constricting blood vessels in the skin, and heat production is increased by shivering. If body temperature decreases despite these mechanisms, hypothermia develops.
The individual’s thinking becomes sluggish, and movements are uncoordinated. heart, respiratory, and metabolic rates decline.