Shorts. High heels. Cologne.

Even if you’re just an occasional air traveler, you probably know better than to wear any of those on board. Heavy perfumes can fog up the cramped aircraft interior, sickening your cabin-mates. High heels? Uncomfortable on longer flights and unusable on those inflatable emergency slides. As for shorts, once the cabin door is closed and the air conditioning is cranked all the way up, you’ll be sorry.

What to wear on a plane — or more to the point, what not to wear on a plane — is a hot topic today for a number of reasons. Not only are we heading into the warm summer months, when air travelers commit a majority of these sartorial slip-ups, but the gap between what we should wear on a commercial flight, and what we do wear, appears to be widening.

Take Kyla Ebbert, for example. She was almost tossed off a Southwest Airlines flight last summer because attendants claimed she was “dressed inappropriately.” What was wrong with her outfit? Watch the video and decide for yourself. Since then, there have been a string of too-skimpy-to-fly incidents, including one in Burbank, Calif. and another in Tampa, Fla.

Curiously, all of these run-ins with the fashion cops have involved Southwest Airlines crewmembers. The carrier insists it doesn’t discriminate against beautiful young women.

Before the airline industry was tragically deregulated, everyone knew what to wear on a plane. People dressed in their Sunday best. Coats and ties for the men. Modest dresses for the women. And kids, who were seen but not heard, were dressed like porcelain dolls.

Now anything goes.

Oh, where is Mr. Blackwell when we need him? Here, in the meantime, are five tips on what you shouldn’t wear on a plane:

Uncomfortable or dangerous shoes
Doug Lynch has a thing for high heels. He doesn’t like to see them on a plane. In his opinion, pumps are problematic — from the discomfort they cause on long flights to the potential trouble they can create in the cabin interior. “Not to mention you shouldn’t wear them going down a slide,” says Lynch, who works for a defense contractor in Melbourne, Fla. I second that. I’m partial to multipurpose, comfortable shoes like the pair of Ecco Xpedition shoes I recently tested. (Another bonus: they’re easy to slip out of at a Transportation Security Administration screening area.)

Light colors
Darker clothes travel better, for a number of reasons, including the simple fact that a spill or stain is less likely to be noticed on a dark garment. And given the airlines’ dismal record on lost luggage, you should assume you’ll have to wear the same clothes tomorrow — and maybe even the day after that. The no-lights rule is especially important for longer trips. “White and lighter colors do not work when traveling unless you can do your own laundry or trust the hotel to do it and have that sort of budget,” says John Shore, who owns a public relations company in Dallas and travels frequently.

Tight-fitting pants — or anything else that’s too form-fitting
If Southwest’s flight attendants were looking for a reason to stop Ebbert and all of the other pretty girls from boarding, then maybe they should have invoked their well-being. Tight clothes can be uncomfortable, and even hazardous to your health (ever heard of Deep Vein Thrombosis, also known as Economy Class Syndrome?) Kate Tyminski, a home inspector from Bluffton, S.C., says tight clothes are a no-no for her plane trips. “I wear loose clothing,” she says. “If you are going to sit awhile on a long flight, you don’t want to have anything on that is binding. The seats are already uncomfortable. Why make it worse?” Why, indeed.

Synthetic fabrics
“Nylon underwear?” says Veronica St. Claire, the chief executive of a nonprofit organization in Los Angeles. “Very bad choice. Steamed tamale time.” Natural fibers like cotton are better choice. Except for wool, maybe. I try to avoid it if at all possible, except during the winter.

Anything with a strong odor
If you wear a powerful-smelling deodorant or cologne, you might consider abstaining before boarding. You may not have any reservations about slathering the aftershave on, but the passengers sitting next to you almost certainly will. If enough of your cabin-mates complain, they may compel you to move — possibly off the plane. “People shouldn’t wear perfume or other strong fragrances,” reader Meredith Weiss told me. I agree. In public places like the cabin of an aircraft, where air is recirculated, giving yourself a pre-trip fumigation may be even more offensive than dressing immodestly.

I know what you’re thinking. What am I, the fashion police? And besides, what’s left to wear, now that I’ve ruled out most of your wardrobe, and especially the fun attire.

Answer: I’m an amateur fashion cop, at best. (As a stay-at-home dad, I spend most of my day in pajamas, so I’m in no danger of making the cover of GQ.) But there’s still lots you can wear on a plane.

Think comfortable and elegant. You want something relaxed and natural that you could spend a few hours or days in without losing the circulation to your limbs. At the same time, you want to look as if you belong in first class. Because crewmembers do judge their passengers by the way they dress — just ask Ebbert and the other young women who were shown the door on their flights — and a blazer or a nice dress can mean the difference between a pleasant flight and no flight at all.

Jim Penrose, a computer specialist from Los Angeles, says he applies the “dress for success” rule on his flights, particularly to international destinations. “It never hurts to dress nicely,” he told me. “People in other countries may have a much higher sense of what is respectable and respectful, in terms of clothing.”

With a little planning, we can too.