There are some things about flying that we don't miss.
There's the cutting of toenails while seated, the snoring passenger spilling over the armrest and onto your shoulder. Oh, and also that one person who reheats pizza on board – using the overhead light as a warming device. Who could forget that one?
The viral image, which has resurfaced on social media, shows a man attempting to reheat his food using the reading light above his head, leaving users baffled how it could possibly work.
Shared on the popular Instagram account Passenger Shaming, the image shows a passenger's arm outstretched above his head with a slice of pizza in hand.
The image, which was first shared on social media in 2016, with social media users flooding the recent re-post with hundreds of comments.
"I love pizza but aren't those LED lights? Do they omit heat? I only ask because we have LED stop lights here in Colorado and if we get a blizzard and they get covered up the light doesn't melt the snow," one critic questioned. "Ridiculous".
"This is just sad. Sad slice and sad attempt to make said slice edible," another wrote.
Some however defended the concept, labelling it as "genius".
"I feel this is innovative instead of disgusting," one wrote.
"It's like an Easy Bake Oven for the world traveller. If a light bulb is good enough to cook brownies its good enough for pizza," another said.
"I don't hate this, pizza over feet any day is fine by me," another added.
When it comes to bizarre behaviour at 38,000 feet, it's no surprise there's plenty of it.
Earlier this year, a plane passenger was left horrified after spotting a stranger's dirty feet on her headrest.
The rude passenger put his feet just above her head during the flight.
The image, posted on a forum on Reddit, shows a woman frowning at the camera.
Behind her are two bare feet looking dirty, slightly crossed as they rest on her headrest.
The picture is captioned: "This is the one thing I am most worried about before getting on a plane."
It isn't clear who the person is in the picture.
However, the picture has had nearly 1000 comments in agreement that it was disgusting.
One person wrote: "I think we should just ban other passengers."
Another added: "Ew those are some dirty a** feet."
Last August, a plane passenger was disgusted after a man put his bare feet on the in-flight entertainment screen before leaving toe marks on the wall.
American Comedian Andy Richter shared the images on social media.
Along with the images, he explained how he managed to get him to take them down.
He wrote: "So I snitched this f***er out to the flight attendant, who told him to put them down.
"Puts them back a few minutes later and I asked him to put them down. 'They're your bare feet, man.'
"He was shocked and put them down. When he just put them back up I decided f**k it, I'm tweeting.
"We had to get off the plane because of lightning and there were dirty toe smudges where his feet were."