Which of the following is a common symptom of heat exhaustion?

Heavy sweating is indeed a common symptom of heat exhaustion. This condition typically occurs when an individual’s body temperature rises due to prolonged exposure to high temperatures and physical exertion, particularly in conditions of high humidity. As the body struggles to cool itself down, it produces sweat in an attempt to dissipate heat. This excessive sweating often leads to the loss of electrolytes and fluids, and while the skin may feel cool and clammy as the body tries to regulate its temperature, the prominent symptom you would observe is significant sweating.

In the context of heat-related illnesses, it's important to recognize that while heavy sweating occurs, other symptoms—including rapid heart rate and feelings of weakness or faintness—can also emerge as the body's physical condition continues to decline due to further dehydration and lack of adequate cooling.