I stay warm with a fire in the fireplace
It's been a cold winter here in the Bay Area. Yes, it's been colder on the east coast (even in Florida!) and for some people, low-40s isn't cold at all, but it's been cold FOR ME.
My preferred method of staying warm during the winter is lighting a fire in the fireplace and curling up under a blanket with one or more cats. I'll turn on the central heat if necessary but prefer not to.