Never Forget to Put This on Before Flying, Experts Warn

Always use sunscreen before flying.

You already know you should be wearing sunscreen every day (yes, even on the days you stay inside). But did you know that rule applies to air travel, too? Turns out, it does. "The sun's rays are much more harmful at the in-flight level, and we should all be wearing sun cream when flying," says Enrizza Factor, MD, clinical dermatologist and medical and health writer with MyEczemaTeam.

Factor notes that most plane windows block UVB rays (the ones that lead to sunburns and skin cancer) but that UVA rays (the ones that lead to some skin cancers, as well as premature signs of aging, fine lines, and wrinkles) can still penetrate the glass. Because your skin is so much closer to the sun at a higher altitude, it can do more damage than it normally would.

There is a relationship between frequent flying and skin cancer.

Just because the plane window should block out most cancer-causing UVB rays doesn't mean you can skimp on sunscreen. One 2015 study published in the Journal of the American Medical Association Dermatology found an increased incidence of melanoma in pilots and cabin crew.

During the study, the researchers discovered that the UVA dose at 30,000 feet in Las Vegas, Nevada, was approximately 242 µW/cm²—compare that to the UVA dose in a UVA-only tanning bed, which is 706 µW/cm². A few more calculations found that pilots flying for 56.6 minutes at 30,000 feet receive the same amount of UVA carcinogenic effective radiation as they would from a 20-minute tanning bed session. The researchers note this radiation could be even higher when flying over clouds and snowfields, which can reflect up to 85 percent of UV radiation.

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Try this in-flight sunscreen routine.

Fortunately, there's an easy way to prevent sun damage while flying: use sunscreen. The dermatologists we consulted recommend applying a thin film of SPF 30 or higher with UVA and UVB protection on all exposed areas of your body (think face, arms, chest, and neck) an hour before you fly. Then, apply a small amount every three hours after that.

If you have acne-prone skin, you'll also want to take that into account—especially as cabin pillows, sweat, and grime can trigger a flare-up. "The best sunscreens for people with acne-prone skin will also be water-resistant," says Yoram Harth, MD, board-certified dermatologist and medical director of custom acne treatment MDacne. "Physical sunscreens that are based on zinc oxide and titanium oxide can clog the pores of people with acne-prone skin and should be avoided."

Don't forget to hydrate, too.

The final step in preparing your skin for takeoff is hydration. "Our body loses water through respiration at a high altitude when flying," says Jeffrey T.S. Hsu, MD, board-certified dermatologist and founder of Oak Dermatology. "It has been shown that it can be twice as much, twice as fast as it does at sea level." To counteract this, Hsu says there is no better hydrating skincare than drinking water itself.

If you'd like to take things one step further, try a hydrating treatment. "Some of my patients tell me they bring hydrating sheet masks on the plane," Hsu says. "That's a topical method and can provide temporary hydration on the surface of the skin, but nothing beats true hydration from the body." With SPF and a glass of water, you'll be ready to hit the skies.

RELATED: Never Forget to Do This Before Boarding, Flight Attendant Warns.