Look at you, leisurely sweating cobs in your short-sleeve tee, completely oblivious to the Autumn chill that's about to beset your poor, deprived forearms.
A smart dresser knows that you've got to start thinking about your transitional baking-to-freezing jacket right this very second. But don't worry: there's no need to splash out on new threads. Just reach for that old denim dust-collector at the bottom of your wardrobe.