I'm terrified of flying. Not for the obvious reasons like being a mile high and wondering why my oxygen mask bag might not inflate. No, I dread flying because, for the past two years, I haven't been able to board an airplane for any length of time without also finding a new pimple somewhere on my face. Once the pattern emerged, I became a devout practitioner of the storied "in-flight skincare routine." I did a chemical peel in the Delta terminal at JFK. I liberally patted on Dr. Sturm Hyaluronic Serum aboard a non-stop to Berlin. I marinated in Charlotte Tilbury's clay mask the second I arrived at my hotel in Santa Monica. Didn't matter. Something new always cropped up. Acne and travel seemed two peas in a first class, flatbed pod.

Right before the holidays, I decided to try the weirdest tip for in-flight breakouts I'd heard in recent memory. An aesthetician had told me in passing, some months earlier, that she always flies wearing a liberal layer of sun block. Obviously the rays are stronger the higher up in the atmosphere you go, but the more relevant reason was the barrier it creates. She was convinced that a physical block would literally shield her face from the onslaught of bacteria in the cabin. Moreover, it should help keep moisture from seeping out of your face cracks (pores). I didn't buy it at the time. But by the end of 2017, I had very little left to lose. If I was going to break out anyway, I may as well add an experiment into the mix.

The thing is, it worked. So well, in fact, that I've been able to travel, arrive, and watch my skin continue to improve onsite. It makes vacationing and traveling for work more enjoyable. I haven't been this excited about a beauty tip maybe ever.

Of course, you need a very good sun block to get the full effect. In terms of physical protection, I throw my full support behind Dr. Jart's Cicapair Color Tiger Grass Correcting Treatment with SPF 30. It's a mix of titaniam dioxide, zinc oxide, and green pigment that helps neutralize redness—so much so that it almost looks like you're wearing a BB cream. (Less makeup-y though.) Before my recent slate of travel (Chicago then Utah then Stockholm then Copenhagen), I decanted a bit of it into a teeny-tiny Muji jar—the 1.7 oz. full-size package is TSA-OK, but far more than you need. Honestly, I probably won't work through all this product until next September. So if you're worried about price, just know it'll last you.

Now, before you run and tell me off for succumbing to a tip that conveniently lines up with happenstance and a renewed effort to restore my moisture barrier even when I'm not traveling, know that I have backup. I learned just last week that Glossier's own Kelly Mittendorf relies on the SPF-in-flight trick and endorses as heartily as I do. Plus that rogue aesthetician. Three's a trend! Chime in below and we'll see if we can make an even bigger crowd.

—Emily Ferber

Photographed by the author.

You've got your sun block packed—but what else? Try this list.