When a character is feverish and requires a thermometer, there will often be a joke about using it in an inappropriate orifice. This takes two main forms; either the thermometer is being used in the incorrect end, or it's being used in the correct end and the victim simply doesn't want it there. Subtrope of Toilet Humor and Ass Shove.
- In a commercial for Huggies diapers where a baby uses a sock puppet to express how he really feels, he reminds his mom that they make thermometers that go in your mouth.
- One of the Luvs diapers commercials involves a pair of new parents figuring out how to take their first daughter's temperature, and it's implied in the commercial that they used the other kind of thermometer on her. Come their second daughter, they had a different method of checking her temperature.
- In Okusan, the titular housewife becomes ill and her husband buys a thermometer to check her temperature. It's not until he gets home that he realizes that in trying to find the most accurate type of thermometer, he bought a rectal one. In a variant of this trope, the husband is incredibly flustered over the mistake while Okusan is perfectly fine and tells him to go right ahead with using it (that she and her husband have a very active sex life probably made it much less awkward for her).
- A Futurama comic book involved Cubert being sick and complaining of how Doctor Zoidberg used the rectal thermometer rather than the oral one. Zoidberg did in fact use the oral one, but "had bad aim".
- There's a joke early in the movie Idiocracy in which the main character is given a brief examination. He's told that a specific probe that he just had in his butt is actually supposed to go in his mouth.
- In Carry On Nurse, the staff decide to get revenge on an insufferable patient by swapping out his rectal thermometer for a daffodil and taking a photograph of him. Leads to one of the funniest scenes in the whole series:
The Colonel: Come come, Matron. Surely you've seen a temperature taken like this before?Matron: Yes Colonel. But never with a daffodil!
- A doctor is making his rounds through the hospital when he stops to talk to the head nurse. The nurse says , "By the way, doctor, did you know you've got your thermometer stuck behind your ear?" The doctor feels around his ear and says, "Great, some asshole has my pen."
- Things Mr. Welch Is No Longer Allowed to Do in an RPG, item 520: "Under no circumstances is my medical droid allowed a groin-mounted rectal thermometer."
- In an interesting variation, one of the winners on America's Funniest Home Videos was a little girl who thought she was taking her temperature. Turns out what she'd taken for a thermometer was a used pregnancy test.
- In one episode of Everybody Loves Raymond Marie takes Ray's temperature and when she checks it, she thinks that it's wrong. She then takes out another thermometer and tells Ray to roll over.
- Variant in the show ER: Garrett Morris plays a patient who annoys the staff so much that they finally make up a pretext to take his temperature— and then leave him with a sunflower up his ass.
- On House, Dr. House's first encounter with villain Tritter begins when House sticks a rectal thermometer up Tritter's butt and leaves it there for several hours.
- In the Pilot episode of M*A*S*H, someone accidentally uses a rectal thermometer as an oral thermometer.
- Used as a threat in an episode of The Suite Life of Zack and Cody, wherein Cody warned his mom to stop talking with the thermometer in her mouth, "or we'll have to do it the other way."
- MythBusters did this one in the Goldfinger paint retest. The medics wanted Adam's core body temperature taken, which, of course, meant a rectal temperature probe. When Adam learned this, his reaction was priceless. Later, just as the deed is about to be done:
Adam: Oh, Sanjay, Sanjay, will you respect me tomorrow?
- Later episodes requiring a core temperature reading had the hosts swallow small thermometers with radio transmitters in order to avoid that level of embarassment again. Hence, "I ate a radio for science!"
- One The Far Side cartoon has an image of a scientist with a giant thermometer approaching the backside of a dinosaur:
"An instant later, both Professor Waxman, and his time machine are obliterated, leaving the cold-blooded / warm-blooded dinosaur debate still unresolved."
- In Get Fuzzy, Rob takes Satchel's temperature when he's sick, and Satchel wants to know why he's putting the thermometer in his ear. He knew it wasn't an oral thermometer, but apparently he'd been using it somewhere else...
- Liberty Meadows: Leslie the Hypochondriac Bullfrog rushes into Frank's office claiming to be sick, and yanks the thermometer out of Frank's hand and puts it into his mouth to prove it. Frank tells him it's not an oral thermometer. "Jeopardy!" Thinking Music ensues, and then Leslie spits it out.
- Scandinavia and the World: When Finland gets ill, Sweden warns him they now only have two rectal thermometers because Denmark jumped the gun when told that was the best way to take temperature.
- Something*Positive: Davan refuses a rectal thermometer during a checkup and insists his temperature be taken via "the forehead, ear, or, and this may seem novel, under the tongue". The doctor responds with "Fine, but you're the first person to ask me to stick a rectal thermometer in his mouth."
- In Freefall, Florence, an anthropomorphic wolf, asks Winston, a veterinarian, if he could please use an oral thermometer during an exam. Winston replies that "This type of thermometer is faster and more accurate, and you know it." The last frame shows Florence looking uncomfortable, while Winston has a thermometer in her ear.
- Comes up in Doc Rat, of course.
- Madagascar: Melman presents Marty with "my first rectal thermometer" for his birthday and doesn't tell him where it's been until after Marty's had it in his mouth. Admittedly Marty, being a zebra, has no hands ...
Melman: You know, that was my first rectal thermometer.Marty: MOTHERF— (spits thermometer out)
- In the same franchise as the above example, in The Penguins of Madagascar, Julien makes a comment about being glad he's not a mammal. Kowalski proves him wrong by checking various points of mammalhood, including warm blood. It's not really shown onscreen, but the Hammer Space thermometer and Julien's expression make it easy to guess how he does this.
- An episode of The Fairly OddParents had Vicky become nice. After she checked Timmy's temperature, Cosmo remarked that she remembered to use the correct thermometer.
- Done, of course, in The Simpsons when Grampa is looking after Bart in the episode "Marge Gets a Job".
"Oral thermometer, my eye! Think warm thoughts, boy, 'cause this is mighty cold."
- An second season episode of Total Drama Island, "One Flu Over the Cuckoos", does this. When everyone but Leshawna and Duncan are sick, Duncan attempts to put a rectal thermometer in Harold's mouth.
- From the Futurama episode "Parasites Lost", when Zoidberg uses a camera to see what's inside Fry.
Zoidberg: Now I'm going to put this camera inside of you.Fry: (opens his mouth)Zoidberg: Guess again.Fry: (his eyes go into Oh, Crap mode)
- Recess: School's Out had a well-hidden one snuck in, in the scene where T.J. accidentally runs into the sliding glass door to his house and freaks out his parents. When his mother worries that he's given himself a concussion, she tells him to wait while she runs off to get "the baby thermometer and the petroleum jelly". T.J. understandably bolts at the mention of petroleum jelly.
- In the short, "Concord The Kindly Condor" from the Tiny Toon Adventures episode, "Toons From the Crypt", a bear gets caught in a trap. Concord arrives, takes out a thermometer, and walks towards the bear's rear. The next shot is a close-up of the bear's satisfied face, surrounded by hearts. This gag is then revealed to be subverted, as Concord merely used the thermometer to pry the trap open so the bear could get free.