Final answer:
When people get too hot in response to extreme temperatures, the body increases blood flow to the skin's surface to facilitate heat loss through sweat evaporation and radiation. The body employs several mechanisms, including dilating blood vessels, increasing sweat production, and altering the depth of respiration. In contrast, in response to cold, the body reduces blood flow to the extremities to conserve heat.
Step-by-step explanation:
The correct answer to the question regarding human adaptation to extreme temperatures is that when people get too hot, the body responds by increasing blood flow to the surface. This physiological response is designed to promote heat loss and regulate body temperature. During exposure to high temperatures, blood vessels in the skin dilate, allowing more blood from the core to flow to the surface, thereby permitting heat to radiate into the environment. As a result, sweat glands increase output, and the evaporation of sweat from the skin's surface assists in cooling the body. To further manage high heat, a person's rate of respiration may increase, and breathing may occur through an open mouth, increasing heat loss from the lungs.
It is incorrect to say that areas of high temperatures result in people who are short-limbed, or that humans have the same number of sweat glands regardless of the environment. Additionally, the statement that in response to getting too cold the body increases blood flow to the surface is incorrect; in fact, the body conserves heat by reducing blood circulation to the extremities during cold conditions and employs mechanisms such as shivering and increased metabolic activity to generate heat.