“Mad dogs and Englishmen go out in the midday sun.” The English actor and playwright Noel Coward knew what he was talking about when he wrote that. Sometimes you can’t stay indoors when the sun’s rays are strongest, though. And it is important to protect your skin from ultraviolet radiation at other times, also.

You can do this in three ways: Use a sunscreen or sunblock or wear protective clothing. A sunscreen is a chemical that you apply to your skin that absorbs ultraviolet radiation and prevents the skin from tanning and burning. PABA is a well-known ingredient in sunscreens; benzophenone 3 is another. You can buy sunscreens in several different forms: in creams, lotions, or gels that may also be waterproof or water resistant, and more.

The most important thing to look for in choosing a sunscreen is the sun protection factor (SPF). If your skin turns red and burns after 20 minutes in the sun, a sunscreen with a SPF of 3 would protect you against sunburn three times longer (60 minutes) than if you had not used one.

Sunscreens rated SPF 15 screen out 95 percent of UVB rays. This is sufficient for most people. Those who are fair, and those with a history of skin cancer, may need a higher number, such as 30 or more.

Taking certain kinds of medicine can make your skin more sensitive to ultraviolet rays. Sulfa drugs, antibiotics such as tetracyclines, and certain tranquilizers and antidepressants are among these. People taking these medicines may need to use a higher SPF, stay out of the most intense sun, and cover up. This should be discussed with a physician or pharmacist.

Remember to apply your sunscreen about 15 to 30 minutes before you go out in the sun, so your skin has time to absorb it. Adequate, even coverage is more important than gobbing on a thick layer. Your skin will let you know if you forget any spots, but by then it’s too late. Don’t forget your ears, nose, lips, and scalp as well as behind the neck and knees and tops of feet. Reapply your sunscreen regularly, especially if you are swimming or perspiring.

It All Adds Up

Passive sun exposure — those little 10- or 20-minute mini-bursts of sunshine as you go about your business every day — really adds up. This is one of the best reasons for making sunscreen a habit, like brushing your teeth or putting on a seat belt. Keeping a tube handy will reinforce the habit.

A second way to protect your skin is by using a sunblock. This substance literally blocks the ultraviolet rays. Zinc oxide is the best known sunblock. It is often applied to the nose, shoulders, along a part in the hair, and other very sensitive areas. It even comes in some pretty hot colors.

Covering up is the third form of skin protection. Light-colored, loose-fitting clothing is best — a longsleeved shirt, pants, a beach robe. Top it off with a wide-brimmed hat to protect your face, and sunglasses.

Further Dangers

Exposure to ultraviolet radiation affects parts of the body other than the skin. UVB rays are absorbed by the lens of the eye, and over the years they can cause the lens to become cloudy rather than clear. This condition is called a cataract, and interferes with vision. In rare cases, too much exposure to infrared or ultraviolet rays may cause permanent damage to the retina or cornea, and even blindness.

Sunglasses offer the best protection. It is the material they are made of, and not how dark their tint, that blocks UVB rays. Plastic lenses allow only five percent of the rays to pass through. Glass lenses also screen out ultraviolet rays. Wearing a hat with a brim reduces exposure by half.

The body’s immune system is not immune to the effects of solar radiation either. UVB rays weaken the immune system’s Langerhans cells so the body isn’t able to mount its best defense against germs and defective cells.

Don’t give up. The sun may not be as innocent as a yellow smiley face, but neither is it instant death. The key is to acknowledge the dangers that exist, protect yourself against them, and then go and live your life. May the sun shine on you — safely, we hope.