One of the side effects of eating at Curryworld in Red Dwarf was firebreathing after the first mouthful. Kryten didn't quite get the programming right...
Lampshaded in a Saturday Night Live sketch with Christian Slater. He and Victoria Jackson go to a restaurant to try the Buffalo wings, available in mild, medium, hot, or "super fire hot'. Slater says he wants to try the super fire hot. The waiter tries to talk him out of it — "They're very hot" — it escalates, the manager is called out to explain "They're very hot" — finally he has to sign release forms — he bites one, freeze-frame, and then the conventional effects of the trope are narrated in detail by a voice-over. The final joke is that he did all that, and they had secretly given him the medium-hot wings.
Played straight in an episode of Everybody Loves Raymond. Frank loses his sense of taste as a result of a side-effect of some herbal pills he got from a friend (for his "foot"), and can't taste anything; at first, Ray and Robert think it's just that he can't properly taste Marie's cooking, so they give him a loaded quiche with jalapeno peppers, wasabi sauce, and horseradish. When he doesn't react to that either, Robert eats the rest to check if they got something wrong. Turns out that their mix was just fine.
In one episode of Bottom, Richie invents a dish called "sprouts Mexicaine" which turns people into Fire Farting Diners.
Played for laughs during a scene transition on Home Improvement. Al had been asked to fill in as host of a cooking show, with Tim as his assistant (in a reversal of their usual roles on the Tool Time show). Tim accidentally eats some hot peppers and scrambles around the scene to try to find a way to cool his burning mouth, concluding just before the transition with Tim guzzling down milk, then spraying flame into the air as Al smiles for the camera.
In an episode of Parks and Recreation, at a dinner party at Leslie's house Ron eats a whole red pepper which impresses his date, who happens to be Tom's ex-wife. A jealous Tom tries a pepper as well, despite Ron's warning. Immediately after popping it into his mouth he has to leave the table. He spends the rest of the party in Leslie's bedroom with sucking a pillow, because his mouth feels like it's on fire.
The Muppet Show: after preparing a batch of Blazing Inferno Hellfire Sauce, steam is released from the Swedish Chef's ears. When he goes a bit overboard with the "pepper saucen" to finish the sauce, his hat is blown clean off by the resultant explosion, which is accompanied by the same volume of steam you'd get from boiling the Great Lakes. No actual fire is seen, though.
In Reno911, the sheriff's department was being sponsored by Hottie's Hot Wings, with all the hot wings they could eat. Even the mild wings were incredibly spicy. But the real fiery sensation didn't occur until a few hours after eating...
Dept. Kimball: I feel like I've been gastrointestinally raped!
Death in Paradise: He doesn't end up literally breathing fire, but in episode #3.4 Inspector Humphrey Goodman accidentally eats a Scotch bonnet pepper, thinking it is a tomato. He is then shown being force-fed vast quantities of milk, as this the only alternative to taking him to hospital.
This is the result of eating one of the samosas made by Indie's grandfather in the How to Be Indie episode "How to Have Your Samosa and Eat It Too".