What is a common risk factor that lifeguards should be aware of?

Swimmer fatigue is a critical risk factor that lifeguards need to monitor closely. It can significantly impair a swimmer's physical abilities and judgment, making them more susceptible to drowning or accidents. When individuals become fatigued, their strength and coordination diminish, increasing the likelihood of distress in the water. Lifeguards are trained to recognize signs of swimmer fatigue, such as a decrease in swimming speed, difficulty keeping afloat, or struggling to stay at the surface. By being vigilant about swimmer fatigue, lifeguards can take proactive measures, such as providing rest breaks or, if necessary, intervening to assist distressed swimmers before a situation escalates into an emergency.

Other options, while relevant to swimming safety, do not directly correspond to an immediate risk factor like swimmer fatigue does. For instance, excessive hydration is not a common issue in the aquatic environment and typically wouldn't lead to immediate dangers during swimming. Wearing appropriate swim attire is certainly important for comfort and safety, but it's not as direct a risk factor in terms of immediate dangers as fatigue. Lastly, capacity limits of the pool relate more to crowd control and preventing accidents rather than the individual risks posed to swimmers.