Analysis of human thermoregulatory mechanisms using 2-D computational model.

A numerical investigation is reported comparing various human thermoregulation mechanisms under hot and cold stress. The passive system of the developed model consists of 12 spherical/cylindrical segments and is modeled using the Pennes bioheat equation and finite difference method. The active system accounts for all regulatory responses, including the counter current heat exchange between veins and arteries; the respiratory heat loss; and threshold, gain, and maximum intensity of response mechanisms. The developed code analyzes various thermoregulatory defense mechanisms under hot and cold environments. Results indicate that shivering and sweating are more effective than other defense mechanisms under cold and hot conditions, respectively. Suppressing shivering will be more effective than the stoppage of vasoconstriction for inducing therapeutic hypothermia. The normal basal metabolic heat generation is essential to maintain a constant body temperature. It is seen that the changes in threshold temperatures of thermoregulatory mechanisms significantly affect the core more than the peripheral regions. The result may be helpful for better management of therapeutic hypothermia, hot/cold stress management, and design of drug protocols.