It's been really cold here--temperatures are expected to be below freezing for 2 or 3 days.
This morning when I got up, my house was 51 degrees F. That's despite having the heat turned up and leaving three space heaters running all night. (I'm not looking forward to seeing the power bill!)
I don't know how cold it got in the middle of the night, but I woke up around 4:30 with a cold nose like you get from going outside in chilly temperatures.
I guess that's one downside of living in a 90-year-old house!