We had to turn on our heater

So for the past two winters, we have managed to not turn on our heater. We always stayed warm with our little space heater and from the guy below us-we always said "Mike kept us so warm" which is weird when you first hear that, but really, he did. See, our theory is that all the heat from his apt rose up into ours and since there is a flat roof (no attic or anything) on our building the heat just stayed in our apt. So we were nice and warm. But unfortunately for us, Mike moved out this year, I think it was some lame excuse like he got a post-doc fellowship for his biomedical engineering at Stanford, I mean come on, what is more important- that or keeping us warm? Anyway-he moved out and now there is no one under us. So no more hot air to rise up. After a few miserable weeks and three blown fuzes (we bought another space heater to try to keep things warm but instead it just blew the circuit all the time) we thought, we should just suck it up, turn on the heater, and pay our gas bill. Although to put it in perspective of how inefficient our furnace is, our heating bill is about the same as my parents, only my parents live in a two story, couple thousand square foot home and we live in about a six hundred square foot apartment. thus, we really liked not having to turn on our heater. but we dislike being cold more so we turned it on. but it is so warm and toasty in here, it is totally worth it and we don't have to sleep with two pairs of pajama pants, three long sleeved shirts, a fleece jacket, two pairs of socks, and five blankets to stay warm (that really is no exaggeration, that is what I was sleeping in during some really cold nights).