Heat in New York apartments is a fickle thing. See -- and I don't know if this is the case with apartments in other cities, but people who have always lived in houses are sometimes surprised to learn it -- you don't turn it on or off, or pay for it; the landlord does. We have these steam radiators with valves, so you can regulate how much heat comes through, but not when. The result is that sometimes my home is like a sauna and sometimes no heat comes through for hours and hours. Because the landlord pays for it, of course it's in his best interest to provide as little heat as he can get away with, but fortunately there are laws. One of them is that he's not allowed to shut off your heat for nonpayment of rent. That's a good development; time was when he could kind of try to murder you if you went broke during the winter.
Because my parents read this, I should make it clear that my particular landlords are actually pretty good about providing enough heat. Which is good because one of Nineveh's favorite things is to insert herself under the radiator like a pork chop under a broiler.