Once your body adjusts to a climate, it reacts differently to previously "normal" temps. When we first started spending winters down here I would be in shorts all the time with never more than a sheet on the bed all winter. A couple years ago I went out and bought an electric blanket and I use that puppy a lot in the winter. I dug out my hoodies and fleece jackets and I wear them as soon as the sun goes down from Dec to Mar. If it is 70°F I am in a big coat and long pants with the heater on in the car
My friends who come down for a few weeks are laughing that I think it is so cold but it 'feels' cold and that is all that really matters. That said, I'm ready for a little chill, nights are still close to 80°F and snuggling under that electric blanket sounds pretty good. Nothing below 70° though, that's my limit for cold. If I were just choosing a place to live based solely on weather I would be very close to the equator and not have to deal with changes in temps at all.