WASHINGTON — Right now, the U.S. is experiencing one of its first heat waves of the summer, specifically in the Northwest, where cities in Oregon and Washington hit more 115 degrees according to the National Weather Service.
With the atmosphere getting toasty outside, its always a good reminder to wear sunscreen.
If you take a peek online, you'll find lots of people sharing tips about just how often to reapply. Lots of people claim that you should reapply sunblock every two hours when you're out in the sun.
So we're verifying, is that true?
THE QUESTION
Should you reapply sunscreen every two hours?
OUR SOURCES
- Centers for Disease Control and Prevention - "Sun Safety"
- American Cancer Society - "Choose the Right Sunscreen"
- Dr. Adam Friedman, professor and chair of dermatology at The George Washington University School of Medicine and Health Sciences
THE ANSWER
Yes, but you may need to reapply more frequently if you're swimming or sweating.
WHAT WE FOUND
Our Verify researchers found out pretty quickly that this piece of advice circulating online is true; All our experts say you’ll want to reapply sunscreen every two hours.
"We know that after about two hours, the sunscreen ingredients don't work as well to protect you, and so that reapplication is just to, once again, make sure you're being protected from the harmful and carcinogenic effects of the sun," Dr. Adam Friedman at The George Washington University said.
But that's two hours with an asterisk: you'll need to reapply if you get wet.
"The caveat to that though, is if you are coming out of a pool, or out of the ocean, or you are working out and sweating profusely and you wipe off, the recommendation is to reapply right then and there, as for any sunscreen at most they'll confer up to 80 minutes of water protection," Friedman said. "So that's a good time to reapply even if it's under two hours."
The CDC agrees—sunscreen wears off.
So how much sunblock should you be using? Dr. Friedman says you’ll want to slather on a shot-glass full, or about 1.5 ounces.
"This is roughly the amount of sunscreen you would need to cover the areas that will be exposed when when outdoors," Dr. Friedman said.
So we can Verify, yes, in general you should reapply sunscreen every 2 hours while outside.