My studio apartment is often 69 - 72 degrees, even with the heat all the way off. The joys of not living in a detached single home.
A few weeks back, I noticed my radiator stopped working all together. The weather was mild, but I thought I should get it fixed anyway.
Turns out the valve that regulates the radiator gets clogged if the radiator is off most of the time. A maintenance person, who happens to be a coworker from my job (small world), unplugged the valve. He suggested I turn up the heat a couple of times each day so debris, that flows in pipes, can flush out. They have a trap, down in the boiler room that collects debris. There is always a bit of debris in pipe systems, I guess.
So now I turn up the heat with little, or no guilt about energy conservation. I turn it up when I'm sitting at my computer and not very active. The space often goes to 75 degrees while I'm sitting passively. Then I turn it down at night for sleeping or while I'm away.
The joys of living in a building. The utilities are fully covered by my reasonable rent. This winter has been quite cozy.