The answer is ‘radiating excess body heat into the
environment’. Vasodilation of cutaneous
blood vessels shunts blood closer to the surface of the skin. This allows dissipation
of heat to the environment. This is also ideal if there is a breeze in the environment
to facilitate this process (the reason why people us fans in hot days). If the
body is unable to shed this heat (maybe because it is too hot in the environment)
then the person may experience heat stroke