What may not come to mind for some travellers, however, is that the public transport they are about to board may not always be cleaned thoroughly before each journey. 

Experts have revealed to Reader's Digest the places on an airplane where germs most commonly hide and what not to do during your flight to stay healthy and comfortable while airborne. 

Before boarding that plane, the most important thing to remember is not to feel embarrassed to tell a flight attendant when you are not feeling well. 

Read also: Five innovations that could transform air travel

Don't walk around barefoot

Anything could have fallen on the carpet, as flight attendants reveal they have seen "everything from vomit to blood to spilled food hit the carpet". 

“We see people walking from their seats into the bathrooms all the time barefoot and we cringe because those floors are full of germs,” said Linda Ferguson, a flight attendant for 24 years, as quoted by Reader's Digest. 

Don't turn off the air vent over your seat

Keeping the air vent on is important to help blow airborne germs away from your personal zone, with doctors recommending that it should be set to medium or high in flight. 

Travellers should instead consider adding on a layer by wearing a jacket or sweatshirt when they start to feel chilly, rather than turning the air vent off. 

Don't let your food touch the tray table

The tray tables reportedly do not get sterilized between every flight. Stephen Morse, professor of epidemiology at Columbia University’s Mailman School of Public Health, says the tray tables are usually wiped down once a day or when the plane goes into an overnight station. 

“Those tray tables are used for all kinds of things,” said Ferguson. “During flights, I’ve seen parents changing babies on top of tray tables. I’ve seen people put their bare feet on top of tray tables.” 

Although samples of a study tested negative for potentially infectious bacteria, such as E. coli, it did find that the trays harbor an average of 2,155 colony-forming units of bacteria per square inch.  

Other items to keep in mind that may have been used by others without getting a thorough cleaning before getting to you include blankets and pillows. 

Read also: The dirty dozen: UN issues list of 12 most worrying bacteria

Don’t snooze against the window

Remember that others have sat on the very same seat you're on and may have pressed their head against that wall too. Not only that, just think maybe they have even sneezed and coughed on the glass you're about to lean on.  

“I see plenty of people carry Lysol wipes with them that will wipe the area around their seat,” said Ferguson. 

A rule of thumb, he said, is never to put your hands in your mouth or near your face. It is also recommended to avoid wearing shorts and instead, try to wear clothing that covers the skin from the seat. 

Don’t touch the flush button in the bathroom

With the bathroom notoriously known as a major place where germs hide out, Catherine Sonquist Forest, a primary care doctor at Stanford University Health Care, suggests to avoid touching the flush button without a towel to protect your skin.

“When you go to the bathroom, the right thing to do is always wash your hands, dry your hands with a towel, and then use the towel to turn off the water and even open up the door,” Forest said. (liz/kes)