The consequences can range from catching germs to being put on a No Fly list. But even if the penalty is merely looks that could kill from your fellow passengers, there are things you simply should never do on a plane. First-time flier or veteran business traveler, read and heed this list of eight air travel “don’ts”:

Raise a ruckus

The flight is late, you’re tired, you’ve got lots of unpleasant issues waiting when you get home. But you still can’t indulge the impulse to start ranting, whether you direct your remarks to a single passenger or crew member or to the world at large. If you are loud, rude or disrespectful, expect a lifetime ban from the airline. Causing a commotion might even earn you a spot on the No Fly List that’s part of the Terrorist Screening Database maintained by the TSA. Naturally, you’d face the same sort of restrictions if you got in a fistfight. But verbal disputes or aggressive remarks aren’t just unpleasant for everyone, they can cause dire consequences for the perpetrator.

Walk around in your bare feet

Even if you typically would never nap with shoes and socks on your feet, make an exception for sleeping during air travel. Bare feet on a plane aren’t restricted, but they can pick up some really gross germs from the floor in front of your seat and of course anywhere on the aisle. Remnants of blood, urine or vomit are not all that unusual. And if you walk through the crew’s area barefoot, you also run the risk of stepping on glass shards if anyone has dropped a glass.

Drink water from the cabin’s tap

No one would ever order tap water when the drink cart comes down the aisle. But it’s worth knowing that flight attendants also use the often-poor quality tap water on board to make coffee, tea, and ice, so you should avoid all of the above.

Have a carbonated beverage

Yes, between no beverages made with tap water and this restriction, your drink choices do get narrowed to juice, canned wine or liquor shots from a sealed bottle. But increased altitude makes the intestinal gas from carbonated beverages expand by as much as 30 percent. If you’re not concerned about your own stomach pains, have mercy on your fellow passengers. They won’t appreciate your gas emissions after you drink a soda or mixed drink made with seltzer or cola.

Forget to bring something warm to wear

The air in the plane can get chilly. While you can take care of that somewhat by turning off the adjustable air above your seat, that causes another issue. When the air isn’t circulating, every germ in the cabin is stagnant right in your personal space. Instead, make sure to bring a sweatshirt or light wrap to cuddle up in when the cabin gets cool. Don’t rely on the availability of an airline-provided blanket or pillow for this, either. Both are notorious for being recycled from flight to flight without ever getting washed until the end of the day. Also on the topic of comfort versus germs, don’t wear shorts on the plane. If you do, you’re bound to get cold. And even if you’re tough and wear shorts all winter, when your exposed legs come into contact with airport and airline seats, you’ll pick up every germ and bodily fluid from recent occupants.

Sit down the whole flight

This is a health risk that’s earned the nickname “economy-class syndrome” and you don’t want to be the next victim. When you sit for a long time, especially in high altitudes, you put yourself at risk of developing a blood clot, usually in your legs. You can reduce your risk of this deep vein thrombosis (DVT) by walking the aisles for a few minutes once every hour, or at least standing up to stretch. If that’s impossible, risk looking a little eccentric and exercise in your seat. The idea is to twist your torso from side to side and then lift one knee and then the other to your chest. Another good tactic is to wiggle your toes a few times an hour. Also, make sure you don’t wear binding clothing when you fly since it can cut off your circulation and pose another risk of DVT.

Attempt to join the Mile High club

If you have dreams of joining the “Mile High” club, aka having sex on a plane, you probably shouldn’t. While most crews will probably ignore you or roll their eyes, it’s an absolute germ fest in the lavatory. And since you can’t exactly ask about this ahead of time, you do run the risk that you’ll be on an airline or flight where the crew has been told to alert the captain to such behaviors. That’s where indecent exposure charges come in.

Be a big jerk

These are the toughest behaviors to avoid on a plane. That’s because the people who would ever think of doing these things probably aren’t worried about their impact on fellow passengers. But here’s a timely reminder never the less: Avoid all socially unacceptable actions in flight The top “don’ts” are probably noise violations, since they affect the whole cabin. So don’t watch a movie on your handheld device without wearing earphones (or let your kid do it) or hold loud conversations with your hard-of-hearing friend across the aisle. Eating smelly foods (talking to you, tuna wrap fans), elbowing the person in the middle seat, or smashing other people’s carry-ons in the overhead compartment to make yours fit are other no-nos. But you already knew that, right?