Know Your Sunscreens!

Know your sunscreen: physical blocks and chemical blocks protect your skin in different ways.

When those first rays of warm summer sun hit our skin--before the muggy humidity kicks in--it's hard to resist soaking it up for hours. But basking can quickly become baking, and the next thing you're dealing with is sunburn, wrinkles, or an increased risk of several skin cancers.

Cover your skin The best way to guard your skin is to shield it from the sun.

* Wear wide-brimmed hats, sunglasses, and sun-protective clothing. When you swim, wear a wetsuit, advises Alan Dattner, M.D., a holistic dermatologist in New York. And, if possible, stay out of the midday sun.

* Eat more brightly colored fruits and vegetables and drink green tea. High in antioxidants, they can help your skin repair sun damage and fight potentially cancer-causing free radicals, says Dattner.

* Apply an effective sunscreen. Whenever your skin is exposed, slather on a lotion high in SPF.

Read labels

Not all sunscreens are alike. It helps to understand the ingredients and know which rays they'll protect you from.

PHYSICAL BLOCKERS Minerals like zinc oxide and titanium dioxide are used in physical blocks, which provide the most comprehensive coverage: They sit on top of your skin and reflect the rays of the sun, shielding what's underneath, explains Kenneth Beer, M.D., a dermatologist in West Palm Beach, Fla.

CHEMICAL BLOCKERS Ingredients used in chemical blocks soak into your skin (instead of sitting on the surface) and help prevent damage by breaking down harmful ultraviolet rays.

WHAT SPF MEANS Sun Protection Factor indicates how much shelter you'll get from the sun's damaging rays. To find out how long a sunscreen will shade you, multiply its SPF by the amount of time your unprotected skin can spend in the sun without burning (for most people, this is between ten and 20 minutes, depending on skin type). If you burn after ten minutes, an SPF of 15 will shield your skin for 150 minutes.

WHAT UVA RAYS CAUSE

Ultraviolet A (UVA) rays can cause premature aging, such as wrinkles, and may even cause some skin cancers.

WHAT UVB RAYS CAUSE

Ultraviolet B (UVB) rays are more potent, quicker to produce sunburn, and are a major cause of skin cancer. Because UVB rays cause sunburn, SPF always refers only to UVB protection. To defend yourself from both UVA and UVB rays, look for a physical block or a full-spectrum chemical block.

Slather all over

When applying sunscreen, don't forget your ears, neck, and the backs of your legs--places people often overlook. When you put it on your face, start at the outside and move in, suggests Doris Day, M.D., a dermatologist in New York. "Most people miss the edges of their face, so starting there will help make sure every part is covered."

Physical blocks, which use ingredients like zinc oxide and titanium dioxide to protect against both UVA and UVB rays, are effective immediately--no need to wait before going outside.