Aging and Thermoregulatory Control: The Clinical Implications of Exercising under Heat Stress in Older Individuals

Figure 1

(a) At rest, the rate of (solid line) is balanced out by the rate of (dotted line), a combination of evaporative and dry heat exchange. At the onset of exercise, rapidly rises reaching a steady state within 5 min. Due to the delay in the onset of responses, does not immediately balance the rate of resulting in net heat storage. The additional heat energy stored inside the body initiates increases in sweating and skin blood flow to increase and achieve heat balance to prevent a continuing rise in core temperature (dashed line). (b) When heat balance cannot be achieved, core temperature will continue to rise to potentially dangerous limits and not plateau, due to limited capacity; the rate of required to achieve heat balance is greater than the maximum capacity for heat dissipation. : metabolic heat production; : net heat loss.

(a)

(b)