1 Answer

1.|During exercise, the heat produced in the contracting muscles causes internal body temperature to rise until the heat-dissipation responses, increasingly driven by the rising temperature, provide for a new balance between heat-production and heat-loss rates.

2.|The new elevated steady-state internal body temperature is not invariant, but can be affected by a number of factors, such as wetness of the skin or state of body hydration.

3.|Progressive dehydration, such as occurs during prolonged exercise or exercise in the heat, results in relative hyperthermia caused by increased thresholds and decreased sensitivities of the heat-dissipation mechanisms. Independent manipulations of blood volume and osmolality reveal that these variables exert their effects on the thermoregulatory system by somewhat different means.

 Source > http://www.sciencedirect.com/science/article/pii/0306456583900979