Summer brings with it two sworn enemies of hair—chlorine and sun. To fend them off, follow this advice from celebrity hairstylist Kristan Serafino. Before swimming, wet down and condition (but don’t rinse) your hair to keep it from absorbing chlorine. And when in the sun, pin up your hair in a twist or a chignon rather than wearing it down or in a ponytail. That way, it will be less exposed to damaging ultraviolet light.