What are environmental hazards a lifeguard should be aware of?

The correct answer highlights a range of environmental hazards critical for lifeguards to monitor. Changing weather conditions can significantly impact water safety; for instance, sudden storms may lead to strong winds, lightning, or rough waters, all of which pose risks to both swimmers and lifeguards.

Water currents are another important hazard, as they can create strong rip currents or undertow, making swimming dangerous for individuals, especially those who are not strong swimmers. Lifeguards must be vigilant in assessing these currents to ensure the safety of everyone in the water.

Debris in the water, such as branches, trash, or even submerged objects, can pose physical hazards that may lead to injuries or impede swimming. Recognizing and managing these hazards is vital for maintaining a safe environment at swimming locations.

While the other choices mention relevant safety concerns such as sun exposure and dehydration, they focus more on individual health and safety rather than the broader environmental factors crucial for lifeguard vigilance.