Abstract: A systematical introduction is given to the characteristics of heat exchange in the head with a discussion of the extreme importance of brain temperature maintenance on the whole body responses to heat stress in order to clear up certain mistaken viewpoint thta head cooling is not essential in the design and application of personal thermal conditioned equipment.The physiological mechanism of selective head is given, and further research and systematic analysis on physiology of head cooling will provide the firm medical basis for engineering of head thermal protection.

Key words: cooling, temperature control, blood flow