I don't trust our ancient furnace not to explode or asphyxiate the cats, so when there is no one here to feed the fire the house gets cold. We returned from 3 days away to find the indoor temperature a cool 47 degrees. So cats and humans alike have been lolling downstairs while the fire blasts out enough heat to make the house habitable again.
I never installed any fans to bring the heat up, so I had the boys tie on blanket capes and run up and down the stairs. Effective as well as entertaining.