Often, but not quite always, done for the purpose of Fanservice.
A frequent variation is to have the characters being discovered in a state of entirely innocent dishabille by rescuers who immediately assume they've been taking advantage of time while waiting for the rescue.
Another variation involves deserts, which would actually be a bad idea in real life, on account of loss of bodily fluids, sunstroke, etc. — the stereotypical Arabic costume of robes and head-dress exists for a reason. See also Heat Wave.
- A Kraft Dinner commercial has this. The landlord says to two college roomies that "there will be no microwaves or hotplates in the room", prompting them to turn up the thermostat to cook the mac n' cheese. When one asks the other "think we should turn the heat down now?", the other sees the hot women walking through the halls in their undergarments fanning themselves sexily. You can guess the response.
- Averted in Neon Genesis Evangelion, when Misato refuses to take off anything with Kaji also present in the elevator, despite it really getting hot. Then again, it's mentioned several times that they used to date and went through a painful break-up, so it makes sense from her point of view.
- This happened in the hot room challenge from Kujibiki Unbalance (the one where they told scary stories).
- In The Big O episode "Call From The Past", Angel and Roger Smith are trapped in a building underwater. Angel takes off her dress (leaving her in her lingerie) and afterwards is shown fanning herself, indicating that she did it because she was feeling hot. It starts around 3:55 on this YouTube video. BTW, this is Fanservice, an indication of UST, and a way for Roger to see the very symbolic scars she has on her back (which make Roger wonder if his constant tease of calling her a fallen angel might have some real meaning). :)
- Snow strips down to a tank top when she fights in the Volcano field in M─R. (She usually wears two jackets, Unfortunately, it doesnt end up helping her much (fire is just not her thing; her name means something as she's an ice specialist).
- Happens near the beginning of the anime Please Teacher! when Kei and Mizuho are locked in the gym storage room.
- Done on purpose by Naru's little sister Mei in Love Hina, in order to get Keitaro to notice Mutsumi more.
- Happens rather late into Hayate the Combat Butler. While Maria tries to show Hayate the old mansion sauna, the lights go dim and they both trip and get stuck to the floor. The temperature was unbelievably high and they tries to get out but Maria got her skirt stuck to the floor forcing her to take it off (and forcing Hayate to look away). Sadly, Haytate accidentally sees her panties and is thrown in the dungeon for the remainder of the day.
- The Radio Drama of UFO Princess Valkyrie has a two-episode story where child Valkyrie accidentally traps everyone inside an improvised sauna. All of the girls (except for Akina, of course, due to the presence of Kazuto as well as Risa for being absent the entire radio series) remove their clothes to cool off. Somewhat subverted in the fact that Akina actually does start getting dangerously dizzy and faint from the heat due to not stripping.
- In A Certain Scientific Railgun, Kiyama Harumi tends to use this trope whenever it gets hot, far below Sauna of Death levels. She is always stopped by other female characters about halfway through.
- In an episode of Megaman NT Warrior, Mr. Match cheats in a net battle by raising the temperature of the stadium in an effort to get Lan to faint. Some people in the audience start doing this.
- In 1982's one-shot all-humor issue The Fantastic Four Roast, Spider-Man asks Johnny "The Human Torch" Storm to turn off his flame as it was getting a little too warm.
Johnny: No chance, pal. The fans came here to see the Human Torch. The flame stays on.
Spider-Man: Fine. I roast you, you roast me. Seems fair.
- Element-inverted in one Marsupilami book: An archeologist couple find themselves in a stone pit with a wall statue pouring water, threatening to drown them. The wife takes off her jacket and tells her husband to do the same, he wonders if this is really the right time, she gently chides him and clarifies that they need to block the flow of water coming in.
- Fantastic Four (2005) had Johnny Storm repeatedly utilizing his newfound fire powers to put this trope in action while riding in a elevator.
- Christmas at the Riveria, a 2007 Christmas drama, features the Mistaken for Cheating variaton.
- In Ace Ventura: When Nature Calls, things got a bit hot for the title character whilst spying on someone from within a tank disguised as a rhino. After stripping bare, he finds that the tank door is jammed, so he crawls out through the rhinobot's vagina, meaning that a safari-going family got to witness a rhino giving birth to a fully-grown, naked human.
- Betsy Parker's character does this to herself — deliberately turning up the heat to give her an excuse to disrobe — in the 1983 teen sex comedy Private School.
- In Spiders II: Breeding Ground, around the end of the movie the lead character Alexandra gets totally covered by steam and takes off her black shirt and continues the reminder of the film in her grey tank top.
- In Age of Dinosaurs Jade Jacobs locks herself in a small confined to protect herself from the Dinosaur, after spending some time there while waiting for get freed, she removes her coat.
- In Firequake four scientist get stuck on underground tunnels that they end up getting sweaty, so they removing their containtment suits, the female scientist also removes her regular shirt alongside the containtment suit, remaining in a tank top.
- In [REC], with the movie being set in a apartment building crowed with many panicked tenants and also having to carry an injured elder cop downstairs its naturally going to get hot, Angela takes off her red jacket and white shirt, remaining in a tank top, she also starts to get more sweaty as the movies goes on.
- In Speed Zone, Charlie (John Candy) and Tiffany (Donna Dixon) are rammed by a vehicle that is pursuing them. This damages the car's cooling system and the engine starts overheating. Charlie cranks the car's heater up to full to pull heat off the engine while they escape. The interior heats up to the point where they both start stripping off their clothes: thereby providing both Fanservice and Fan Disservice in the one scene.
- Nancy Drew, of all people, gets caught in this trope during Two Points to Murder when she's locked in a basketball team's sauna. She removes shirt, jeans, socks and shoes, which (though it's not expressly mentioned) leaves her in her underwear when she finally figures out how to escape.
- Arthur C. Clarke's A Fall of Moondust: A tourist moonbus, buried under several metres of dust has its air conditioning fail, because the radiators are buried, leading to all of the passengers shedding most of their clothing.
- Nyssa supposedly takes off her jacket and then her skirt in the Doctor Who serial "Terminus" because she is running a fever from Lazar's disease, but it was so out of the blue and poorly explained that it has become a running joke among Doctor Who fans.
- Primeval: Season 1 has Abby keeping her pet lizard Rex in tropical temperatures, requiring her to walk around in her underwear. A new season and a change of timeline later, she seems to have lost the habit.
- Friends parodied this, with Joey turning up the thermostat:
Rachel: It must be like 100 degrees in here!
Joey: Is it so hot you want to walk around in your underwear?
Joey: Still not enough!
- (The middle lines are often cut in re-runs, resulting in a rather odd non-sequitur.)
- Also parodied in one of the first episodes of The Big Bang Theory, when the guys are all trying to redesign Penny's apartment. Penny, who's perfectly happy with it as it is, says something along the lines of, "It's getting hot in here, I think I'll take off all my clothes" to get their attention. Completely unsuccessfully.
- Done completely straight in a Season One episode of Ashes to Ashes, with Alex Drake and Gene Hunt locked in a secure and near-airtight document vault. Alex strips down to her underwear and Gene breaks out a hip-flask just in time for Ray and Chris to arrive and break them out.
- Played for laughs in Monty Python's Flying Circus with a scene outside a tower block with a young lady changing in the window (and the lines "My it's hot in here" badly dubbed on). Later this scene is itself parodied where Ramsay MacDonald is the "My, it's hot in here" stripper.
- Spoofed in the recurring Saturday Night Live segment "How Do You Say?... Ah, Yes!... Show," where Chris Kattan played a very randy Antonio Banderas. The sketch always ended with Kattan "innocently" remarking "It is hot in here, no?" and tearing off his shirt to the accompaniment of a flamenco guitar before trying to "seduce" (i.e. date-rape) his female guest.
- In an early episode of Farscape, an alien decides to lay eggs and hatch its young in Moya, and has to increase the heat in order to properly incubate the eggs properly. Aeryn ends up going into heat delirium (a potentially fatal condition her species is susceptible to, due to their being unable to deal with excessive heat). She does her best to lower her body temperature by removing some clothing, followed by taking a cold shower. Since heat delirium is apparently a very unpleasant way to go, this is not played for Fanservice. (Much.)
- In an early episode of Eureka, Sheriff Carter's smart house stages an intervention to keep him in town. When short-circuiting the AI causes it to revert to an earlier personality, a miitary interrogation AI named BRAD, the AI separates the six people into groups of two. Carter and Alison are in a section of the house that's freezing, while Douglas Fargo and Beverly Barlowe are in a section that is getting unbearably hot. Beverly finally removes her dress, asking Fargo to look away. Marginal Fanservice, since her slip isn't much more revealing than her dress (save for maximum cleavage) and the difficulty is resolved moments later and the dress goes back on.
- Modern Family: The Dunphy's next door neighbour Walt used to keep the temperature in house high so the meals-on-wheel lady would have to take her sweater off.
- In Knight Rider 2008, KITT is hit by a missile containing a napalm compound, putting it on fire. The invulnerable car can take it, but the heat is rising fast inside (as well as the oxygen depleting). Inside, Micheal and Sarah, to last a bit longer while KITT and the Knight Foundation are looking for a solution, strip down to their underwear.
- Star Trek: Voyager. Captain Janeway returns to Voyager to find the crew infected and immobilized by an alien virus, that eventually leaves the body and grows into a large and hostile Monster of the Week. As the environmental controls are no longer working Voyager can't vent any heat, so the audience is gifted by a Lock and Load Montage in which our Action Girl strips down to a sweaty tank top and grabs a compression phaser rifle to get Sigourney Weaver on the creatures' butts.
- Happens to the entire cast of Victorious in the episode "Survival of the Hottest" (save for Cat), when the main characters are accidentally locked in an Recreational vehicle during a Heat Wave.
- The song "Hot in Herre" by Nelly. And the video clip, of course.
- In Something*Positive, Nerdrotica's heater won't shut off and all the phone sex operators have stripped down to their underwear. Jason is horrified that Davan is actually trying to get it fixed.
Jason: Do you wake up every morning and say, "Today, I'm going to find someone's dream that's come true and put an end to it"?
Davan: I look at it like this: the holiday season may have a phenomenally high suicide rate, but we can't hope to maintain that level of excellence if everyone doesn't do their part.
- Stick Man Stick Man plays with this in strip 692: the heros are stuck in a car lifted by a helicopter over a volcano, so one of them suggests this.
- Happens in the My Little Pony: Equestria Girls fan comic Caught in the Storm on page 7: in which Twilight Sparkle, Applejack and Rainbow Dash get stuck on a storm in AJ van, so they decide to sleep on the van for the night, Rainbow Dash reluctantly strips herself to her underwear after it starts to get hot inside the van.
- Code Lyoko: Used to play up the Unresolved Sexual Tension for all it was worth between Ulrich and Yumi in episode "New Order", as seen above. And to much frustration, they still remained Just Friends.
- Seen when Fry and Bender flood their prison cell with steam in an ill-conceived escape attempt and decide to use it as a sauna.
- Also when Amy and Fry get stranded on Mercury in her new car.
- Happens in the French animation show Il Útait une fois... l'Espace (Once Upon a Time... Space), at the beginning of the "Revenge of the Humanoids" story arc. The spaceship of Peter and Psi crash-lands on a desert planet and the internal heat regulator is busted, leading the male and female leads to strip off their tops. The desert part of the trope is then averted when they venture outside, though, as they wear heat-repellent suits.
- Happens to Shifu in one episode of Kung Fu Panda: Legends of Awesomeness when he's trapped inside a metal box with a Descending Ceiling (spiked edition).
- In Jurassic World, Claire starts out wearing white business attire, but slowly abandons more clothing and becomes sweaty as she spends more time running around the hot jungles of Isla Nublar. Given it's Bryce Dallas Howard, you can't really complain.
- In Transformers: Revenge of the Fallen both Sam and Mikaela spend the last moments of the movie running in the hot Egyptian deserts trying to reach NEST, by near the end of the conflict they get rid of their jackets.
- In the 2008 Journey to the Center of the Earth film, the group discovers that the temperature on the center of the Earth will rise to the point they will die, after this, Hannah Ásgeirsson abandons her grey shirt for a white tank top.
- Most of the characters in Predator, considering the movie is set in the jungles of South America. Anna ditches her shirt, spending the remainder of the film in a tank top, while the male characters all end up shirtless.
- In one of Aesop's Fables, the titular North Wind and the Sun try to strip off a man's cloak in order to determine which of them is strongest. The Wind blows and howls till he nearly lifts him off his feet, but the traveler only wraps his cloak tighter. Then the Sun burns down, and the man abandons his cloak by the side of the road.
- The Dresden Files: Harry Dresden frequently wonders whether this day is a "too hot to wear my bulletproof duster" or "too bullet-y to worry about heatstroke" sort of day. Given the Dresdenverse, no matter what he decides, it's the latter.
- Primeval: Helen justifies her usual lack of clothing as her travelling in historical eras where it is much hotter than the present.
- In Broken Saints, Oran takes his shirt off when crossing the desert... at night, when it would be very cold. (Considering he lives in that climate, you think he'd know better.)
- In The Marvelous Misadventures of Flapjack, Flapjack and K'nuckles climb a mountain and assume it's going to be hot at the top because it's closer to the sun, so they do this. Of course, they were wrong about the top of the mountain being hot....
- At the beginning of the "Revenge of the Humanoids" story arc in Once Upon a Time... Space, the spaceship of Peter and Psi crash-lands on a desert planet and the internal heat regulator is busted. This leads the male and female leads to strip off their tops. The desert part of the trope is then averted when they venture outside, though, as they wear heat-repellent suits.