The Effects of Heat
The human body is designed to function at an optimum temperature of 37 Degrees Celsius. If the temperature falls too low we start to shiver. Our muscles twitch and this generates heat. If the temperature gets too high we start to sweat and the evaporation of liquid from our skin carries away heat. Heat can have other effects, some therapeutic, some not.
The therapeutic application of wet or dry heat may increase circulation and produce hyperemia, accelerate the dissolution of infection and inflammation, increase absorption from tissue spaces, relieve pain, relieve muscle spasm and associated pain, and increase metabolism. Blood vessels will dilate near the surface of the skin, allowing more blood to flow and allowing more heat to be dissipated. The metabolic rate will increase, there will be a decrease in blood pressure, increase in pulse rate and circulation, and increase in depth and rate of respiration.
The therapeutic application of heat tends to be local and the effects remain local. If the whole body is subject to sustained high temperature, the body's own mechanism to regulate temperature may be unable to cope. This may result in:
Heat exhaustion is characterized by significant sweating, loss of color, cramps, fatigue, fainting and dizziness. Heat stroke symptoms include a body temperature over 103 degrees Fahrenheit, dry skin, high heart rate, confusion and even unconsciousness.
Heat stroke requires immediate attention. If the condition is not treated organ failure and brain damage may result. The body's heat loss mechanism has stopped working properly, resulting in a dangerous increase in internal body temperature. The skin becomes hot, dry, and red. The victim may or may not be sweating. Other signs include a rapid pulse, dizziness, nausea, headache, visual disturbances, and fainting. Breathing may become uneven or shallow and rapid. The victim should be moved into cool shade if possible