 When Rhoda Baker left Southern California to teach school in a northeastern town, she didn't know how cold the winters could be. No matter how many blankets she piled on the bed, she'd wake up in the early hours shivering. So she stopped at a department store one day after school and told the sales girl she wanted a nice, warm flannel nightgown. It doesn't have to be glamorous or pretty. I have a dresser drawer full of those, and if I wore all of them at once, I'd still freeze to death.