How Sunburn and Sun Tans Work

There is something mysterious about the sun and skin. Why is it that if you go out on a bright summer day and spend an hour in the sun, you get a sunburn? You get a sunburn, that is, unless you happen to have taken the time to get a gradual tan. With a tan you can go out in the sun and nothing happens. Of course, that doesn't apply if you have "fair skin." The fair skinned among us never get a… » Full Story on HowStuffWorks