Apply sunscreen before you go out

Time to read the label on your next bottle of sunscreen.

Choosing the right sun protection and applying it properly are not only the most important steps to protect yourself from the sun's harmful rays but also the most misunderstood, says Dr. Kenneth Arndt of Harvard Medical School.

"Some think that a quick application of a tanning cream is sufficient and will last all day, but it won't," he says. "Between one-fourth and one-half of all people who apply sunscreens use inadequate amounts, which obviously limits the sunscreen's effectiveness.'' For example, he says, if an SPF 16 sunscreen is put on too thinly, it's actually equal to an SPF 2.

Arndt adds that the effectiveness of sunscreens diminishes within a few hours, and that cloudy and overcast days aren't as safe as you might think.

The best sun protection for your skin starts with a sunscreen with an SPF of 30 or higher. About one ounce, or two tablespoons, is needed for the average adult body. Arndt says that about one quarter to one third of a tablespoon is right for the face.

Sunscreen should be applied to dry skin about 15 minutes before going out in the sun and should be reapplied every couple of hours.

Arndt also notes that, despite popular belief, there is no such thing as a "healthy tan," because every tan is a response to skin damage. The effects of sun damage can be cosmetic: premature wrinkling, age spots, dryness and a leathery complexion. But sun damage also can cause a variety of skin cancers. These include increasing your risk of developing the non-melanoma skin cancers, basal and squamous cell carcinoma, and the most serious -- melanoma.