What does mean in actuality? Our thermostat is set to 64 degrees 24/7 right now. That's fairly cool; we wear layers, wool sweaters, and warm socks! At night, we bundle up under blankets. Our kids actually do better in the cooler temperature; more dry heat only dries their sinuses out and give them MORE congestion. We began this winter at about 66 degrees and have dropped a degree each month....we worked up to it so to speak. And those sweaters and blankets we already own are free to operate!
As you evaluate your budget and seek to reduce costs, consider your energy bills. It's amazing how much you can save over fairly small changes: one to two degrees on the thermostat, bathing your kids every other night insead of every night, turning off lights when you leave the house, etc.