Excessively spicy food invariably results in a (usually metaphorical) blast of flame from the mouth of the diner, often after he or she has quickly turned red from feet to top of head (in the manner of a rising thermometer, sometimes with a distinctive rising "boooOOOP!" or whistling kettle sound effect). Sometimes it may be accompanied by a factory-like steam whistle or a fire alarm sound.
A common subversion is if one character in a cartoon tries to pull this off on another as a joke or part of an Escalating War. The intended victim will always have an insanely high resistance, while the perpetrator, trying it himself in disbelief, will feel the full force of the trope from the tiniest bite.
In Real Life, capsaicin (the chemical found in 'hot' foods) works by directly stimulating the nerves responsible for detecting heat. This fools the brain into thinking the affected area is being burned and causes heat-related effects such as a flushed face and sweating. However, no spice can actually produce real heat, let alone fire - although there are certainly some foods that can make you feel like your mouth is on fire.
The third hottest pepper in the world is the Naga Viper pepper, coming in at a mouth-scorching, sweat-inducing 1,382,118 Scoville Heat Units (for comparison, the Jalapeño ranks 2,500-8,000). It has been trounced in March 2011 by the Trinidad Scorpion Butch T chili, which clocks in at 1,463,700 SHU; and in February 2012 by the Trinidad Moruga Scorpion, which measures 2,009,231 SHU. Hot sauces made from any three of the peppers (or even all of them) have to be stored in glass, because they all corrode plastic like (*click!*) that.
Not to be confused with the Unsatisfiable Customer, for whom the fire breathing is verbal, rather than metaphorical or literal.
- A Dairy Queen Flamethrower commercial uses this, sort of a live-action Spicy burger is spicy. Another with three unfortunate customers.
- A very similar series of commercials for Taco Bell's Volcano Taco used the same trope, namely to determine who stole and ate said Volcano Taco.
- Red Robin only has smoke in this case, but hey where there's smoke...
- A series of Australian commercials for KFC during the 90s used this trope. Unusually the customers didn't seem to be any discomfort while gaining the ability to breath fire. This in the original, and a later one which doubles as a Dumb Blonde joke.
- The commercial for M&Ms' 75th anniversary flavors has Yellow consuming their appropriate ingredients. For Honey Nut he eats a jar of honey and gets attacked by bees. For Coffee Nut he drinks several cups of coffee and gets jittery. For Chili Nut he crams his mouth with red peppers, setting it on fire.
- The Flaming Hot Cheetos commercials have this happen, typically with Chester Cheetah.
- Lucky Luke: Tortillas for the Daltons sees Lucky Luke as the victim of this trope. The Mexican who talked him into drinking tequila just says: "Refreshing, isn't it?"
- A long gout of flames is one of the effects of the Hideous Hangover Cure that Astérix accidentally invents in Asterix and the Laurel Wreath.
- Peter Fox spent an entire week having to live down his girlfriend Denise's April Fool's joke- a chocolate rabbit filled with hot sauce, which he of course ate in about two bites before his mouth was set aflame.
- One strip had Jason cheerfully putting four bottles of hot sauce on his taco so he could breathe fire. He'd been to the dentist, and the painkillers hadn't worn off yet, preventing him from feeling the burn. "Is Novocaine great or what?"
- Things came to a head when Jason and Peter decided to play "Eat That Taco."
Peter: I can eat this taco with two squirts of hot sauce.
Jason: I can eat this taco with three squirts of hot sauce.
Peter: Four squirts.
Jason: Five squirts.
Peter: Six squirts.
Jason: Eat that taco.
Andy: Paige, stay out of this!
- One strip featured Garfield and Jon having a contest to see who can eat the hottest pepper without invoking this trope. Garfield loses after eating a Peruvian Death Pepper.
- In one Garfield Sunday strip Jon accidentally eats some dog food, and when he asks Garfield to brings him something to drink, Garfield obliges by bringing him a bottle of hot sauce. Jon chugs the bottle without looking at it; the next panel shows him clutching his throat, breathing fire, with his eyes wild and hair standing on end.
- Also happened to Garfield on his fourth birthday, because he swallowed his cake before blowing the candles out!
- In several Harry Potter, fics firewhiskey makes the drinker breathe flames for several seconds after consumption.
- In Happily Ever After this happens to Fred and George after their first taste of goblin food. Harry plans to use this in a restaurant, having a "Eat a dish of goblin food and your party's meal is free" hook and sets them to replicating the sensation without the actual flames.
- The Pieces Lie Where They Fell: The human Pinkie Pie does this all over Vix-Lei after eating a cupcake with a tabasco sauce filling. She loves it.
- In the book Hogfather, the wizards are somewhat disappointed that Bilious, the Oh God of Hangovers, doesn't display this as part of the "humorous side effects" of the Hideous Hangover Cure they'd just made for him.
- There is also Mustrum Ridicully's Wow Wow sauce which is so potent that, in Reaper Man, he uses a bottle of it to cause a magic-resistant slime to explode, taking this trope to its logical conclusion.
- The SF short story Buck and the Gents from Space features a young boy from the Southwest US serving a group of aliens a meal made primarily of chili peppers. Their reaction is described as being "sort of like the Apache snake dance, except they didn't have no snakes in their mouths. Maybe they would've preferred a snake, at that." He then offers them some of the hired hand's rotgut tequila to wash it down with, prompting much the same reaction.
- Fire breath inducing black pepper "desserts" are a mentioned treat of Honeydukes in the Hogsmead establishment during Harry Potter and the Prisoner of Azkaban.
- A magic item available in Forged by Dragon's Fire, an Old World of Darkness supplement, is the "ginger dragon", a small candy most often produced in rural China. They produce real fire.
- Mystery Skulls Animated: In the photo on Arthur's laptop in "Freaking Out" he can be seen in obvious pain with a trail of smoke emitting from his mouth from his spicy... milkshake? A closer look reveals Lewis's prankster sister Cayenne laughing under the table with a bottle of hot sauce in her hand implying she put hot sauce in the milkshake.
- My Little Pony: Equestria Girls Digital Series: In "X Marks the Spot", Pinkie Pie eats a sushi roll with too much wasabi, and breathe green fire before dipping her face in a nearby fountain.
- Link from Awkward Zombie likes Super Smash Bros curry so much, he set the group's apartment on fire several times and burnt through his stomach wall.
- Sydney Scoville, the protagonist of Grrl Power, actively searches for this sort of thing, having an extreme love of spicy food. It generally astounds watchers and occasionally turns her breath into something approximating a chemical weapon.
- Ozy and Millie:
- Ozymandias deliberately invokes this trope to impress the matriarch of his extended (draconic) family, and get out of an arranged marriage. He's adopted.
- In a more recent example, the same character makes use of the trope again, this time as part of an attempt to let his friend to go on a field trip without a permission slip.
- StupidFox believes that eating hot chili peppers will do this. It doesn't quite work out the way he'd planned it. StupidFox is kind of strange that way.
- The Whiteboard:
- In one of the Halloween arcs Jinx, already mutated by consumption of Doc's experimental Mountain Dew, drinks some more and snorts fire.
- Another time Howie's new hot wing recipe made fire spurt out of Doc's ears. He thought them a bit bland.
- The same batch of hotwings had the same effect on Doc's new Love Interest here.