Cold enough to...

I would imagine many of you completed that sentence (if maybe only in your head) with ...to freeze the balls off a brass monkey.  Not something to say in polite society perhaps, but in fact the saying's origin is in no way rude or salacious, and has nothing to do with the anatomy of our ape cousins,  Go back to the days of Francis Drake and pirate ships and the like.  Such ships would store their cannon balls on an open-shelved arrangement made of brass and called a monkey.  In very cold weather, the brass would contract, and the cannon balls might fall off.  So there - you and your dirty mind!