What condition could hinder a lifeguard's ability to effectively scan their surveillance zone?

Glare from the sun or lighting is a significant condition that can hinder a lifeguard’s ability to effectively scan their surveillance zone. This is because glare creates bright spots and reflections that can obstruct the lifeguard's vision, making it challenging to identify potential risks or emergencies in the water or on the surrounding beach. The intensity of the light can cause momentary blindness or diminish contrast, impacting the lifeguard’s ability to discern swimmers' movements and any signs of distress.

While other conditions like heavy rain, high temperatures, and strong winds can also affect a lifeguard’s performance, they are less directly tied to visual obstruction. Heavy rain may reduce visibility to some extent but does not usually cause a significant glare. High temperatures could lead to fatigue or discomfort but do not directly impair vision. Strong winds might create waves or affect the environment, but again, the visual impact is not as acute as glare created by sunlight or artificial lights. Therefore, glare poses a more immediate and direct challenge to effective surveillance, making it crucial for lifeguards to be aware of this condition.