Don't make sunscreen mistakes

Sunscreen is one thing we all know we need, but we never seem to have it with us, or apply enough. So we asked Emory internist Dr. Sharon Bergquist for some advice on how to get sun protection right. When it comes to protecting our skin from the sun, Emory internist Dr. Sharon Bergquist says a lot of us are getting sunscreen all wrong.

"The biggest problems are people don't apply enough, and they don't apply it often enough," says Dr. Bergquist.

We'll start with the first issue:  how much sunscreen do you really need?  Dr. Bergquist says more than you think.

"You're supposed to use an ounce.  So that's a gulf-sized ball amount," she adds "most sunscreen bottles are 5 to 8 ounces, so if you're going to be outside all day at the beach, you should be going through about a bottle every one to two days. That's a lot.  Most people don't come close to that!"

Bergquist says you should reapply sunscreen every two hours.  Going by the clock, rather than the SPF.

"A lot of people think SPF on the bottle means how much time they can spend outside. So if they get a really high SPF, they can spend all day outside."

No sunscreen lasts more than 2 hours. If you're going to be in the water, reapply sunscreen more often than that.

“Water resistant sunscreens are good, at best, 80 minutes. So, they don't even last the full two hours," says Dr. Bergquist.

To pick a sunscreen, Dr. Bergquist says look for the words "broad spectrum" on the label.  That means the product protects against both ultraviolet A and B damage.

You want a sun protection factor or SPF of at least 15, though 30 might be best. A higher number doesn't add up to a lot more protection.

"SPF 15 blocks 93% of the sun's ultraviolet radiation. Double that to 30 and you're getting 97%. SPF of 50 blocks 98%," points out Dr. Bergquist.

Sunscreen is just first step. Try to stay out of the sun when it's most intense, and protect your eyes and your head, and wear light, protective clothing. 

“So it's good to look at sunscreen, as making you bulletproof - look at as part of your strategy," she adds.

So, again, the basics:  make sure you're using enough, and reapply sunscreen every two hours.

Be careful with children in the sun, because their skin is more sensitive.