heat exhaustion

exhaustion /ex·haus·tion/ (eg-zaws´chun)

1. a state of extreme mental or physical fatigue.

2. the state of being drained, emptied, or consumed.

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heat exhaustion  an effect of excessive exposure to heat, marked by subnormal body temperature with dizziness, headache, nausea, and sometimes delirium and/or collapse.

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heat exhaustion

n.

A condition caused by exposure to heat, marked by prostration, weakness, and collapse, resulting from unrecognized or unavoidable dehydration. Also called heat prostration.

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heat exhaustion,

an abnormal condition characterized by weakness, vertigo, nausea, muscle cramps, and loss of consciousness, caused by depletion of body fluid and electrolytes that results from exposure to intense heat or inability to acclimatize to heat. Body temperature is near normal; blood pressure may drop but usually returns to normal as the person is placed in a recumbent position. The skin is cool, damp, and pale. The person usually recovers with rest and replacement of water and electrolytes. Also called heat prostration. Compare heat hyperpyrexia. See also heat cramp.

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exhaustion

privation of energy with consequent inability to respond to stimuli; lassitude.

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heat exhaustion

an effect of excessive exposure to heat. See also heat exhaustion.

physical exhaustion

occurs most commonly in horses engaged in endurance or marathon events. Also in males engaged in territorial combats; bulls and boars are the usual combatants. There are some lacerations but exhaustion is the main problem. Manifested by lethargy, dehydration, hyperthermia, hyperpnea, tachycardia, muscle tremor and some muscle spasm, restlessness, anal relaxation, unwillingness to stand, fidgeting while down, pale cyanotic mucosa and poor capillary refill time.

exhaustion syndrome

in a fit horse normal levels of function in the cardiopulmonary system should be regained within 30 to 60 minutes of stopping work. This is unlikely with horses that are exhausted and which have the following clinical signs—lethargy, dehydration, hyperthermia, hyperpnea, tachycardia, muscle tremor, restlessness, relaxation of the anal sphincter, reluctance to stand, pale mucosa, poor capillary refill and a respiratory to cardiac rate ratio of greater than 2:1. Called also exhausted horse syndrome.

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heat stress disease

Critical care A group of conditions due to overexposure to or overexertion in excess environmental temperatures

Heat stress-forms in increasing severity

Heat cramps Non-emergent and treated by salt replacement

Heat exhaustion More serious, treated with fluid and salt replacement

Heat stroke Most commonly affecting extremes of ages, especially the elderly, accompanied by convulsions, delusions, coma and treated by cooling the body and replacement of fluids and salts

Note: The body's reaction to heat is a function of controllable–use of anticholinergics, phenothiazines, alcohol, heavy exercise, clothing, obesity, direct exposure and acclimatization and uncontrollable factors–high ambient temperatures or humidity, lack of air circulation, underlying fever, old age or infancy, ectodermal dysplasia