What's the best way to stay warm when your apt heat is off?

My landlord won't turn our heat on until December 1st, and I live in Toronto so it's like -2 out there. Super chilly. I've got blankets and all but if I turn the oven on and open the door, it sets off my smoke alarm for some reason (which is hardwired to our ceiling, so I can't take it off) and if I run a hot tub to let it heat the place it sets off the g-d alarm too. So anyone have any clever suggestions? Thanks!