What temperature conditions are associated with an increased risk of hyperthermia?

The correct answer indicates that an increased risk of hyperthermia is associated with water temperatures above 82°F and air temperatures above 90°F. These temperature conditions are critical because they can significantly raise the body temperature when individuals are engaged in strenuous activities, such as diving or swimming.

When water temperatures exceed 82°F, the body’s ability to dissipate heat through convection, conduction, and evaporation becomes less effective. This is particularly relevant for divers who may not be as mobile in warmer water, which can inhibit the natural cooling mechanisms of the body. As for the air temperature, moving above 90°F means the ambient environment is hot enough to contribute to the body retaining heat, especially when combined with high humidity levels. This scenario can lead to an overwhelming workload on the body's thermoregulation system, thereby heightening the risk of hyperthermia.

In contrast, the other options present temperatures that are generally considered safer for prolonged exposure without significantly increasing the risk of hyperthermia. For example, lower water and air temperatures are less likely to induce heat stress, allowing the body to maintain a stable internal temperature more effectively. Understanding these thermodynamic principles is crucial in dive medicine as they directly relate to ensuring the safety and health of individuals during underwater activities.