A favourite catchphrase from everyones favourite spaz The Bo
it is used to point out something blatantly obvious after someone has made a mistake, much simmilar to saying mind your head after someone bangs there head.
this paticular line originated when The Bo
pointed out that metal gets hot when heated after someone burnt there hand on an iron bar that had just been in a furnace
this phrase is used in multiple situations,example such as course its not sharp its a football and course its cold, it ice