Ds wears cotton long sleeved and long pants pj's. He has a blanket in his room that he starts off, but generally pushes off at some point during the night.
He wear's these outfits all year long, as in the winter it's a tad cold, and the summer we run the central air, so it's a tad cold too. He's also a VERY hot child though, so if we used fleece, he'd suffocate.