Final answer:
In hot environments, the body cools itself mainly through sweating and vasodilation of dermal blood vessels to increase heat dissipation.
Step-by-step explanation:
The body has various mechanisms to respond to hot environments and attempt to dissipate heat. One of the primary responses is sweating, where sweat glands increase their output to produce sweat. As this sweat evaporates from the skin surface, it carries away heat, thereby cooling the body. In addition, the dermal blood vessels dilate, which enhances blood flow to the skin and facilitates heat loss to the environment. This process of blood vessel dilation is known as vasodilation. These reactions are in contrast to responses to cold environments, where vasoconstriction occurs to conserve heat, and shivering generates additional warmth.