The sun is our friend - it elevates our moods and provides all the Vitamin D we need. But more than 20 minutes of sun exposure a day during high UV index days will age the skin prematurely. It causes immunosuppression, wrinkles, brown splotches, and rough old skin. More importantly, skin cancers are much more common in people with excessive sun exposure. On this show, we talk about the benefits of sun exposure...and the problems UV light causes. We describe how the SPF number is obtained, everything you want to know about sunscreen.