Which symptom could indicate an athlete is suffering from hyperthermia?

Dizziness is a key symptom that could indicate an athlete is suffering from hyperthermia. When the body's temperature rises excessively due to prolonged exposure to heat or strenuous activity, the body may struggle to cool itself down effectively. This can lead to dehydration and disruption of normal physiological processes, causing symptoms like dizziness.

As the body's core temperature continues to rise, factors such as inadequate hydration or energy depletion may cause dizziness as the nervous system is affected. This symptom is particularly critical in the context of hyperthermia because it can also precede more severe conditions like heat exhaustion or heat stroke, which require immediate attention.

The other symptoms provided—pale skin, increased appetite, and excessive energy—are not typically associated with hyperthermia. Pale skin might suggest shock or heat exhaustion rather than hyperthermia, while increased appetite and excessive energy are generally not linked to overheating and are not indicators of a deteriorating physiological state.