COLD I Actually need heat help

I live in michigan and my room is an old cold storage/celler. It was great for the summer because it stayed cool but the fall and winter are bringing me much cooler temps. What is the best way to heat the room and what is the recommended min temp. I know everyone says no hotter that 76 but it will cost a fortune to keep 76 degrees in that room. please help me

im pretty new at all this but i have the same problem,i was told that a propane space heater was great to use because it gives off co2 as well as heating the room.i have to start taking it a little more seriouse because when i got up this morning there was already snow on the ground.ill be checking your thread to see what kinda advice you get...

it may have been karosine,yep karosine not propane sorry its early