Fever Fudge is a type of sweet made by Fred and George Weasley for their Skiving Snackbox. Fever Fudge is designed to make the one who eats it get a high fever within seconds of eating it, but the side effects are large, pus filled boils, which appear at places that the twins don't "generally display to the public", and they make "sitting on a broom a right pain in the" said place. These boils may be eliminated with some Murtlap Essence.