Even Warner Bros. managed to sneak the joke into an old cartoon (I wish I could remember the name of it):

There was a nightclub at the North Pole, and we see a shot of the building's exterior. The neon sign says "Brass Monkey Club".

As far as the other expression, well, here's a story:

This is true, and not a joke - the late Signora V. was a student of Wicca for many years. Not a Priestess, but she did study it for quite a while. (One of my nicknames for her was Witchiepoo.) Sometimes during the winter, just to tease her, I'd go over to her and place a hand on "righty" (or "lefty" - whichever one was closer), look out the window and say, "My God, it is cold out there!" Her eyes would narrow and she would glare at me.

The next few days were a bit hazy, but I have it on good authority that I was snapping at flies with my tongue. But, as they said in Monty Python, "I got better!"

Signor V.