When the weather reports note that it will barely crack 20°F, if that, then, no matter how sunny and pleasant it look from your nice warm office and its window, it is quite likely that you will be very, very, very cold if you walk to lunch. Particularly if you eschew your jacket in favor of just wearing your wool-but-thin sweater.
A hat and gloves would probably be handy, too.
You will, of course, not really realize this until you are half-way to lunch.
I’m just sayin’, y’know?
It’s rather disturbing to go outside when it’s 28°F and feel like it is warm. After yesterday though….it is downright balmy