Lying with your legs in a badger's stomach isn't the most comfortable thing. Bart can't turn off his stomach acids so things can get a bit tingly. It's a lot more comfortable than trying to get through the fire yourself, though. The flesh and fur of a magically fire resistant badger makes a pretty good shield against the flames.

Not everyone thanks Bart after he emerges from the fire and coughs up his passenger. Sometimes they or their relatives are genuinely angry that his charge ended up scratched up, slimy and slightly acid burned.

Being a good-natured civil servant he resists the urge to tell them that had he not done exactly what he did, one of two things would have happened. Either they'd have to wait until the next morning for the fire crew to dig the burned-up corpse out of the ashes, or Bart would come out of the fire, let out a long burp and apologize for not being able to hold his breath quite long enough.

Ending up a bit scratched up and slimy is as good an outcome as one could hope for given the circumstances, really.