Brass monkey (colloquialism)
（重定向自Brass monkey weather）
The phrase "cold enough to freeze the balls off (or on) a brass monkey" is a colloquial expression used by some English speakers. The reference to the testes (as the term balls is commonly understood to mean) of the brass monkey appears to be a 20th-century variant on the expression, prefigured by a range of references to other body parts, especially the nose and tail.