(I'm not quite sure where to put this, so if this is the wrong subforum for this question I apologize)

I am currently in the process of doing research for my hopefully first snake and I'm trying to work out the issue of keeping ambient temps up. From what I understand most rat snakes/kingsnakes need ambient temps at about 75-80* but my room can get down to 65* in the winter. Will heat lamps or CHEs do enough to bring the temps up by themselves, or would it be necessary to insulate the sides of the enclosure as well? Should I instead try to raise the temps of my whole room with something like a space heater?