Final answer:
Hyperthermia occurs when the core body temperature exceeds 99.5°F (37°C) and occurs when the body is exposed to more heat than it can lose. In a humid environment, sweat on the skin's surface is not able to evaporate, leading to dangerously high internal body temperature.
Step-by-step explanation:
Hyperthermia is when the core body temperature exceeds 99.5°F (37°C), making option C the correct answer. Hyperthermia can occur when the body is exposed to more heat than it can lose. When the body is exposed to high temperatures, it responds by increasing blood circulation to the surface and sweating to transfer thermal energy away from the core.
However, in a humid environment, the sweat on the skin's surface is not able to evaporate, which can lead to dangerously high internal body temperature.