What is an indicator of heat exhaustion that lifeguards should recognize?

Heavy sweating and dizziness are key indicators of heat exhaustion that lifeguards need to recognize. When a person is experiencing heat exhaustion, their body has become overheated and is struggling to cool itself down effectively. This often manifests as heavy perspiration as the body attempts to regulate temperature. Dizziness occurs because the body is losing fluids and electrolytes, which can lead to a drop in blood pressure and reduced blood flow to the brain. Recognizing these symptoms is crucial for lifeguards to take early action and provide necessary care to a person affected by heat exhaustion, potentially preventing a more severe heat-related illness, such as heat stroke.

The other symptoms listed in the options do not accurately reflect heat exhaustion. Fever is not typically associated with heat exhaustion, cold skin indicates a more serious condition such as heat stroke or shock, and rapid weight gain is not a recognized sign of heat exhaustion at all. These distinctions reinforce the importance of identifying the correct symptoms to ensure appropriate response in a lifeguard scenario.