How to Stay Out of Trouble

Skin is the body's largest, most vulnerable organ. Here's some expert advice on how to protect it from overexposure while you enjoy the season:

· Don't rely wholly on sunscreen. Many people forget to reapply it after swimming, sweating or extended exposure. For those with sensitive skin, some products cause rashes. It's better to cover up or avoid rays during midday.

· Learn the language. The SPF, or sun protection factor, is a relative number indicating how quickly fair skin will burn with and without sunscreen. SPF applies only to UVB radiation; there is no standard measure of protection yet against UVA rays. SPF 15 is the minimum protection recommended by the American Academy of Dermatology.

· Eye critically before you buy. The logic behind many new products -- clothing infused with sunscreen, for one -- is questionable, says Washington dermatologist Richard J. Castiello.

Most clothing is protection enough, he says: "You're not going to burn through anything but the thinnest, most gossamer shirt."

· Mind the fine print. Just like milk and coupons, sunscreen expires. A good guideline: Buy a new bottle every summer and keep it away from heat when not in use.

Also, check your prescription meds. Agents in some antibiotics, acne medications and diuretics can become toxic if you take them before direct sun exposure.

· More isn't necessarily better. The Food and Drug Administration has expressed doubt about the value of sunscreen with an SPF number higher than 30. Only those with extreme sensitivity to the sun should spend extra for those products, Castiello says.

Nor does one benefit by putting on a thick, visible layer of the stuff; it's designed to be unseen -- as Castiello puts it, "cosmetically elegant." Better to reapply often.

· Don't hide indoors. Moderate exposure to sunshine is healthy: "When it strikes the skin, it converts oils to vitamin D," Castiello says, and that can strengthen bones and possibly aid in cancer prevention.

-- Emily Lyons