Which characteristic is key to identifying heat exhaustion?

Heat exhaustion is primarily characterized by heavy sweating and weakness. This condition occurs when the body loses too much water and salt through sweat, often due to prolonged exposure to high temperatures and strenuous activity. The body's attempt to cool itself through sweating can lead to dehydration, resulting in symptoms such as weakness, fatigue, and excessive perspiration.

Heavy sweating serves as a critical sign that the body is trying to regulate its temperature but may indicate an imbalance in fluids and electrolytes, leading to heat exhaustion. Furthermore, weakness is a direct consequence of overheating and the body's struggle to maintain normal function. Recognizing these symptoms helps in taking appropriate action, such as moving the affected individual to a cooler environment, rehydrating, and allowing them to rest, thereby preventing the condition from progressing to heat stroke, which is much more serious.

While other choices contain symptoms related to heat-related illnesses, they are not the hallmark signs of heat exhaustion. High body temperature and confusion are more indicative of heat stroke, pale and cool skin can occur in various circumstances, and shivering is typically associated with cold exposure rather than heat-related illnesses.