I heard that it went from 48 F to 15 F in Nashville in a few hours. They are showing the outside of the Hard Rock Cafe on the Weather Channel. I ate lunch there with my wife two summers ago.
Here is some free advice. Don't go outside for a few days. If you must go out, wear layers, cover as much skin as possible. Put some vasoline on your nose, cheeks and maybe your ear lobes. If you jump into your car, take a phone with a charger, a warm blanket, some water and a snack or two just in case. A few hand warmers, like Hot Hands, might be useful, if you can get some. Up here in Milwaukee, you can get them from most Walgreen's and maybe Target stores. They will last up to 10 hours. You can put them in your gloves or boots.
Now is the time to do some baking. Pies, pot pies and pizzas are good to make and eat. Stay warm!