About 97 degrees Fahrenheit. Unlike, say, "hot as hell
" or "scorching hot," this expression is actually fairly precise, since the temperature of one's balls
is carefully regulated by the scrotum
to maintain a high sperm count.
Alice: Man, it is hot as balls out there today.
Bob: Actually, it's about 99 degrees, so it might be "hot as lungs," but balls are slightly cooler.
Alice: ...ooookay, whatever.