Does sunscreen protect you all day?

Most people apply sunscreen when they are going out into the sun but does its protection last for the whole day? Well, the effectiveness of sunscreen is reduced as we sweat, or if it is rubbed off on clothing, and even sunscreens labelled as ‘waterproof’ or ‘water resistant’ can only protect you for up to a few hours when in contact with water or sweat. It’s best to re‐apply sunscreen through the day in those conditions, and also shade your skin from the sun to add a second layer of defence against the harmful effects of UV rays.