If your baby sleeps in his creat it is a good idea to put something over it to keep the draft away. I think you would notice him curled in a little ball or trying to snuggle something if he was too cold. I know when Sassy gets cool she will snuggle closer to the mommy. Infant t-shirts are a good choice for pj's in the winter. You could also get one of those insulated bed liners if you think you need one. You can fill it with either warm or cool water. It works as either...cool bed or warm bed.