Hydration Principles of body temperature regulation Our normal

Hydration Principles of body temperature regulation Our normal body temperature is 37 o. C. This is the temperature inside the body. It remains at 37 o. C because a balance exist between the heat entering and leaving the body. The process is referred to as heat gain and heat loss.

Temperature control The hypothalamus, which is located in the brain, is the body’s thermostat. It reacts when the body’s temperature goes above or below its “set point” at 37 o. C

The heat balance mechanism In healthy individuals, body To is kept within a small range despite large fluctuations in atmospheric temperature. The body continually gains and loses heat. When the amount of heat produced is equal to the amount of heat lost, the body is in a state of heat balance.

Heat production The body produces heat through mainly metabolic processes and exercise. • Metabolism Exercise These tasks, Given its size and accomplished with the weight, skeletal energy produced muscle is able to when adenosine produce heat rapidly. triphosphate splits The more vigorous and then the activity is, the resynthesises, results more heat the muscle in considerable heat produces. production.

Heat Loss Body heat is lost as a result of the following processes • Radiation • Conduction That is, loss of heat in the form of infra-red rays. The greater the difference between the body’s heat and the environment, the greater the radiated heat loss. That is, transfer of heat from a body to an object by contact. Eg heating a pen while holding

• Convection That is, transfer of heat by a moving fluid. A body at rest heats up the air around it, • Evaporation That is, sweating. It is only effective if water evaporates. At rest, in a comfortable environment, sweating accounts for up to 25 % of heat loss.

Heat Balance Heat gain Heat Loss Metabolism Exercise Radiation Conduction Convection Evaporation