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