heat exhaustion

exhaustion and collapse as a result of overheating of the body and loss of fluid following unaccustomed or prolonged exposure to excessive heat. It is more common in hot climates and results from excessive sweating, leading to loss of fluids and salts and disturbance of the ELECTROLYTE balance in body fluids. In the mildest form, which is heat collapse, BLOOD PRESSURE and PULSE rate fall, accompanied by FATIGUE and lightheadedness, and there may be muscular CRAMPS . Treatment involves taking a salt solution, by mouth or given intravenously, and avoidance by gradual acclimatization to the heat, especially if hard physical work is to be carried out.