To add: Don't bundle up into your warmest clothes the first time it gets cold in the fall. Your body will acclimate (at least a little) to colder temps. If you never experience cold your body won't acclimate and you'll just be cold all the time.

Once you've acclimated some you'll probably find that you don't need your heaviest jacket like you thought you would.

Finally sitting around and bitching about the cold just makes you more miserable. It irritates everybody around you too.