Hotter than Hell's hinges
Definition, Colloquialism of the American South, Appalachia (I make a strong distinction between the two, but there are of course similarities).
"Hotter than Hell's Hinges" is the ultimate superlative for a subjective judgement of heat. I've mostly heard it in West Virginia, but if you get far enough into the sticks anywhere south of the Mason-Dixon line, you'll hear it if it gets hot enough.
My father, the pure product of the great state of WV, explained it to me thus, "You know as well as I do that the hottest part of a coal or wood stove, once you really get it ginning, is the hinges. So the hottest part of hell is the hidges on the gates."
It's true about the hinges. Once or twice a winter, dad would really stoke the shit out of the wood stove to burn the creosote out of the flue. Basically, this involved getting a decent fire going, then loading the stove to the top with well-seasoned hardwood (like Oak or Maple). Then throw open the dampers, (this metal flap at the back of the stove and the flapper valve b/w the firebox and the flue). That black iron box would set to drawing, then step the fuck back.
Soon the whole stove would begin to glow a dull red, with the door an almost translucent orange, and the hinges a bright yellow. It was a hell of a thing to see. Made my mother nervous as hell, but my brothers and I loved it, especially once it got to roaring like a jet engine.