I did the same yesterday, with pizza. Pizza cools rather fast, but when we got it at the table it came right out of the oven ... and I was hungry and took a big bite ... big mistake! It still hurts.

Apropos sweet things, I've had the same experience with freshly baked croissants. They seem so harmless as they are fluffy, with lots of air ... but there is butter inside, the butter may be really sizzling hot if the croissants are coming directly from the oven, even if the croissant already has cooled down a bit on the outside.