It isn't possible or practical to completely avoid sunlight, and it would be unwise to reduce your level of activity to avoid the outdoors. Time in sunlight also helps your body make vitamin D, which can be important for good health. But too much sunlight can be harmful. There are some steps you can take to limit your amount of exposure to UV rays.

Some people think about sun protection only when they spend a day at the lake, beach, or pool. But sun exposure adds up day after day, and it happens every time you are in the sun. "Slip! Slop! Slap! … and Wrap" is a catch phrase that reminds people of the 4 key methods they can use to protect themselves from UV radiation. Slip on a shirt, slop on sunscreen, slap on a hat, and wrap on sunglasses to protect the eyes and sensitive skin around them from ultraviolet light.

Following these practical steps can help protect you from the effects of the sun. These steps complement each other -- they provide the best protection when used together.

Cover up

When you are out in the sun, wear clothing to protect as much skin as possible. Clothes provide different levels of protection, depending on many factors. Long-sleeved shirts, long pants, or long skirts cover the most skin and are the most protective. Dark colors generally provide more protection than light colors. A tightly woven fabric protects better than loosely woven clothing. Dry fabric is generally more protective than wet fabric.

If you can see light through a fabric, UV rays can get through too. Be aware that covering up doesn't block out all UV rays. A typical light T-shirt worn in the summer usually protects you less than sunscreen with a sun protection factor (SPF) of 15 or higher.

The ideal sun-protective fabrics are lightweight, comfortable, and protect against exposure even when wet. A few companies in the United States now make sun-protective clothing. They tend to be more tightly woven, and some have special coatings to help absorb UV rays. Some sun-protective clothes have a label listing the ultraviolet protection factor (UPF) value -- the level of protection the garment provides from the sun's UV rays (on a scale from 15 to 50+). The higher the UPF, the higher the protection from UV rays.

Children's swimsuits made from sun-protective fabric and designed to cover the child from the neck to the knees are popular in Australia. They are now available in some areas of the United States.

Newer products are now available to increase the UPF value of clothes you already own. Used like laundry detergents, they add a layer of UV protection to your clothes without changing the color or texture.

Use a sunscreen with a sun protection factor (SPF) of 15 or higher

A sunscreen is a product that you apply to your skin for some protection against the sun's UV rays, although it does not provide total protection. Sunscreens are available in many forms -- lotions, creams, ointments, gels, wipes, and lip balms, to name a few.

Some cosmetics, such as lipsticks and foundations, also are considered sunscreen products if they contain sunscreen. Some makeup contains sunscreen, but only the label can tell you. Makeup, including lipstick, without sunscreen does not provide sun protection. Check the labels to find out.

Read the labels: When selecting a sunscreen product, be sure to read the label before you buy. Experts recommend products with a sun protection factor (SPF) of at least 15. The SPF number represents the level of protection against UVB rays provided by the sunscreen -- a higher number means more protection.

It is important to remember that sunscreen does not give you total protection. When using an SPF 15 and applying it correctly, you get the equivalent of 1 minute of UVB rays for each 15 minutes you spend in the sun. So, 1 hour in the sun wearing SPF 15 sunscreen is the same as spending 4 minutes totally unprotected.

The SPF number indicates protection against UVB rays only. Sunscreen products labeled "broad-spectrum" protect against UVA and UVB radiation, but at this time there is no standard system for measuring protection from UVA rays. Products with an SPF of 15 or higher that also contain avobenzone (Parsol 1789), ecamsule, zinc oxide, or titanium dioxide are likely to be effective against UVB and most UVA rays.

The Food and Drug Administration (FDA), which regulates sunscreens in the United States, has proposed a new set of rules for sunscreen labels. Part of this includes a rating system for UVA protection. Under the new system, sunscreens would be rated from 1 to 4 stars, with 1 star being a low level of UVA protection and 4 stars being the highest. It is not yet clear when this new rule might go into effect.

Check for an expiration date on the sunscreen container to be sure it is still effective. Most sunscreen products are no longer as effective after 2 to 3 years.

Some sunscreen products can irritate skin. Many products claim to be "hypoallergenic" or "dermatologist tested," but the only way to know for sure whether a product will irritate your skin is to apply a small amount for 3 days. If your skin does not turn red or become tender and itchy, the product should be okay for you.

Be sure to apply the sunscreen properly. Always follow the label directions. Most recommend applying sunscreen generously to dry skin 20 to 30 minutes before going outside so your skin has time to absorb the chemicals. When applying it, pay close attention to your face, ears, hands, and arms, and generously coat the skin that is not covered by clothing. If you're going to wear insect repellent or makeup, apply the sunscreen first. For high-glare situations, a higher SPF sunscreen or zinc oxide may be used on your nose and lips.

Be generous. About 1 ounce of sunscreen (a "palmful") should be used to cover the arms, legs, neck, and face of the average adult. For best results, most sunscreens must be reapplied at least every 2 hours and even more often if you are swimming or sweating. Products labeled "waterproof" may provide protection for at least 80 minutes even when you are swimming or sweating. Products that are "water resistant" may provide protection for only 40 minutes. Remember that sunscreen usually rubs off when you towel yourself dry, so you will need to reapply.

Sunless tanning products, such as bronzers and extenders (described below), give skin a golden color. But unlike sunscreens, these products provide very little protection from UV damage.

Wear a hat

A hat with at least a 2- to 3-inch brim all around is ideal because it protects areas often exposed to the sun, such as the neck, ears, eyes, forehead, nose, and scalp. A shade cap (which looks like a baseball cap with about 7 inches of fabric draping down the sides and back) also is good. These are often sold in sports and outdoor supply stores.

A baseball cap can protect the front and top of the head but not the back of the neck or the ears, where skin cancers commonly develop. Straw hats are not recommended unless they are tightly woven.

Wear sunglasses that block UV rays

Research has shown that long hours in the sun without protecting your eyes increase your chances of developing eye disease. UV-blocking sunglasses can help protect your eyes from sun damage.

The ideal sunglasses do not have to be expensive, but they should block 99% to 100% of UVA and UVB radiation. Check the label to be sure they do. Some labels may say, "UV absorption up to 400 nm." This is the same as 100% UV absorption. Also, labels that say "Meets ANSI UV Requirements" mean the glasses block at least 99% of UV rays. Those labeled "cosmetic" block about 70% of the UV rays. If there is no label, don't assume the sunglasses provide any protection.

Darker glasses are not necessarily better because UV protection comes from an invisible chemical applied to the lenses, not from the color or darkness of the lenses. Look for an ANSI label.

Large-framed and wraparound sunglasses are more likely to protect your eyes from light coming in from different angles. Children need smaller versions of real, protective adult sunglasses -- not toy sunglasses.

Ideally, all types of eyewear, including prescription glasses and contact lenses, should absorb the entire UV spectrum. Some contact lenses are now made to block most UV rays. But because they don't cover the whole eye and surrounding areas, they are not recommended for eye protection use alone.

Limit direct sun exposure during midday

Another way to limit exposure to UV light is to avoid being outdoors in sunlight too long. UV rays are most intense during the middle of the day, usually between the hours of 10 am and 4 pm. If you are unsure about the sun's intensity, take the shadow test: If your shadow is shorter than you, the sun's rays are the strongest. Plan activities out of the sun during these times. If you must be outdoors, protect your skin.

UV rays reach the ground throughout the year, even on cloudy days. UV rays can also pass through water, so don't think you're safe if you're in the water and feeling cool. Be especially careful on the beach and in the snow because sand and snow reflect sunlight, increasing the amount of UV radiation you receive.

Some UV rays can also pass through windows. Typical car, home, and office windows block most of the UVB rays but a smaller portion of UVA rays, so even if you don't feel you're getting burned your skin may still get some long-term damage. Tinted windows help block more UVA rays, although this depends on the type of tinting. UV radiation that comes through windows probably doesn't pose a great risk to most people unless they spend extended periods of time close to a window that receives direct sunlight.

If you plan to be outdoors, you may want to check the UV Index for your area. The UV Index usually can be found in the local newspaper or on TV and radio news broadcasts. It is also available on the EPA's web site at www.epa.gov/sunwise/uvindex.html.

Avoid tanning beds and sunlamps

Many people believe the UV rays of tanning beds are harmless. This is not true. Tanning lamps give out UVA and frequently UVB rays as well. Both UVA and UVB rays can cause serious long-term skin damage, and both contribute to skin cancer. Because of these dangers, many health experts advise people to avoid sunlamps and tanning beds.

Protect children from the sun

Children require special attention, since they tend to spend more time outdoors and can burn more easily. Parents and other caregivers should protect children from excess sun exposure by using the measures described above. Older children need to be cautioned about sun exposure as they become more independent. It is important, particularly in parts of the world where it is sunnier, to cover your children as fully as is reasonable. You should develop the habit of using sunscreen on exposed skin for yourself and your children whenever you go outdoors and may be exposed to large amounts of sunlight. If you or your child burns easily, be extra careful to cover up, limit exposure, and apply sunscreen.

Babies younger than 6 months should be kept out of direct sunlight and protected from the sun using hats and protective clothing.