"cold enough to freeze the balls off a brass monkey

Dear Sir/Madam, A brass monkey is a triangle on a ships
deck that holds cannon balls.Why is it
called a monkey.

Type 'Monkey' into the search box at the top to see our past several lengthy posts on this subject! BTW, there now seems to be no evidence that brass triangles were ever used on ships; thus the question is probably invalid!!

My goodness this gets some debate!
If you have ever been on a ship with cannon, you would see the idea is nonsense. (HMS Victory at Portsmouth for example). the pyramid of balls is a largely decorative peacetime situation. No way would cannonballs be stored like that on deck and have the risk of injuring/impeding the seamen. in battle, most non-essential equipment was placed in storage and nimble sailors ("powder monkeys" as it happens) would dash around the ship with munitions as needed.

it is a crude expression, referring to a monkey's genitals - unless anybody knows diferent...