Forced air furnaces have filters that trap dirt and dust. For efficient air flow, they should be cleaned or replaced. Shake reusable filters outside or spray them with a garden hose. Make sure they're dry before replacing. Close chimney dampers.
Warm air rises up and out open chimneys at an alarming rate.
Close your damper as soon as you're certain the fire is completely out. Use sweaters and blankets. Throw an extra blanket on the bed and wear a wool sweater if you home feels chilly. You'll be warm and toasty before you know it. Circulate heated air, since warm air rises, it tends to be trapped in the highest areas of your home.