Isabelles room is about 16-18 overnight - our ducted heating comes on if it drops below aroud 14, but she has a oil filled heater on medium. She wears a S/S jumpsuit, a L/S jumpsuit, a flannel wrap and a polar fleece blanket... sounds like too little although she doesnt wake up in the night cold - although her hands get cold because she hates them wrapped and pulls them out. Her tummy is always very warm when she gets up for a feed.