The best way to prevent skin cancer is to avoid prolonged exposure to the sun, particularly between the hours of 10 a.m. and 4 p.m., when ultraviolet light is at its peak. Use plenty of sunscreen with an SPF of 15 or higher, and wear hats, long-sleeved shirts and pants. Be on the lookout for any changes to your skin, particularly suspicious-looking moles. If you’re older than 40, have a professional examine your skin once a year.