Adapted to the cold weather

When I first got here in the place of my husband, I would always chill with the 73F temperature in our home. I would even open all the vents so that whenever it can give the full heat that I want. But right now, it seems, I am already adapting to the cold weather. I can tolerate with the 68F whenever I will adjust the heater into this number. I am wishing I can adjust to 60F temperature so that we can save a lot of utility bills!