KNR 180 Lecture Notes - Lecture 20: Cardiac Arrhythmia, Caffeine, Itch
20 Apr 2017
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Document Summary
When surrounded by air or water cooler than body temperature, the body experiences heat loss. If body temperature falls much below that, cold injuries can result. The body has two internal mechanisms to maintain body temperature. Stops when core temperature falls between 86 f and 90 f: physical activity produces heat. Heat loss increases if clothes become wet with sweat. The colder the temperature, the greater the potential for body heat to escape. The brain signals blood vessels in skin to tighten, and blood flow to skin decreases. Because of reduced blood flow to skin, skin temperature falls: when exposure lasts more than an hour: Sensation, touch, and pain will be blunted. A person"s ability to perform manual tasks will be impaired: normal body temperature is maintained by a balance of heat production and heat loss. Lack of food limits ability to produce heat.
