Chowder eats a large amount of Dancing Diablos and breaths out the fire everywhere, forcing him to leave the Catering Company.
Mung Daal and Chowder are cooking Dancing Diablos, which are extremely hot peppers. When the Diablos ignite Mung's moustache, he panics, and accidentally releases them. Chowder eats the Diablos to stop them from escaping, but he can't open his mouth without letting out a large stream of fire, since he ate the Diablos raw; he accidentally sets the kitchen on fire. Later, Mung, Shnitzel, and Truffles have to make a dish by singing as loudly as possible. Chowder is banned from doing so, because of the flames. After a few minutes, Chowder eventually snaps and opens his mouth, setting the kitchen ablaze again, ruining the soufflé in the process; he couldn't keep the fire in his mouth for long. Despite this, Mung is angry at Chowder for opening his mouth and sends him to his room without any dinner as punishment. A sobbing Chowder, with his mouth closed writes a goodbye note and leaves, using his hat as a hot-air balloon. Mung goes up to his room to say sorry to Chowder and that he can learn to live being on fire but he finds his good bye note in bad writing. Chowder finds a dragon's cave, and after fire-dueling with one of the three dragons, befriends them. The four have a great time together, until Chowder digests the Diablos via extreme flatulence. He is kicked out and leaves them another goodbye note as one of the dragons looks at him leaving sadly. He returns to Mung, Shnitzel and Truffles to work in the kitchen.
- Powder, a replacement apprentice chef for Chowder resembles Droopy and talks like him.
- The "Fire Heart" song was performed by veteran voice actor and singer Jess Harnell.
- It is possible if the song "Fire Heart" is a parody of the song "Don't mess with Professor Cold Heart" from Care Bears Land Without Feelings.
- Additionally, the song itself may also be a nod to boxing and martial arts movies, such as the Rocky series.
- The Thrice Cream Man made a brief and final appearance in this episode.
- In the "Fireheart" song, it shows a picture of Chowder with Panini, even though he doesn't like her. However, the scene was probably a spoiler for their future relationship.
- He said "Via con Dios", meaning "Be with God", that phrase being the only Spanish phrase he got right.
- This is the first known time Chowder and Mung speak Spanish.
- The episode's song "Fireheart" is also used as the name of a interactive game on the UK Cartoon Network only accessible by the SKY TV service.
- After Chowder sets the kitchen on fire Mung yells at him saying "Look what you've done! Now the animators are gonna have to draw all this fire!"
- After Mung explains to Chowder why he married Truffles he says to "never mention it again" and winks to the camera.
- Mung said "You're interrupting my monologue."
- Chowder burns the background away, including Mung Daal.
- Chowder rips a part of the background in his bedroom and stores it in his suitcase before he leaves.
- Mung is reading Chowders letter and says "It's a good thing I heard the voice over!" since a running gag of the series is Chowder's handwriting being unreadable.
- When Mung is chewing Chowder out for ruining the Open-mouth Barber Shop Souffle with his fire breath, Chowder's mouth opens in fear, yet no fire comes out.
- When the one dragon reads Chowder’s goodbye letter, the dragon had a tear in its eye. In the next scene it can be seen folding its arms in the background looking like its angry at Chowder.