The reason why you needed to put on some pants is because global warming is so bad that the icecaps are melting, and a larger block of ice just slid down your way, and made the weather cold, temporarily, until it melts too, and the whole planet becomes a barren desert.
Makes sense, innit?
PS: If you look out the window, and don't see the ice, I have bad news: the end is nigh, and you shall give me all your keyboards, because the world is ending anyway.