I love to think about how we use language. Today I had fun thinking of all these common expressions that employ the word “hot”, none of which have anything to do with any measurable unit of heat.
Hot bed Hot dog (Noun)
Hot potato Hot dog! (exclamation)
Hot time Hot lips
Hot head Hot money
Hot seat Hot rod
Hot for (Verb) Hot chick/Hot dame
I also thought of these expressions that use the words cold or cool, once again with no connection to actual temperature.
Cold hearted Cool headed
Cold turkey Cold cash
Cool! (adjective) Cold Fish