 Swimming is a good way to cool off on these hot days, but spending all that time in the water can affect your hair and skin. That's because the chlorine that disinfects a pool and keeps the water looking crystal clear can also be very drying. It dries out your hair, it dries out your skin, it strips away your natural oils. Cleveland Clinic dermatologist Dr. Jennifer Lucas says that can lead to a skin rash known as irritant contact dermatitis.