How to Dress Newborn for Sleep in Winter [Safe & Cozy Tips] How to Dress Newborn Baby for Winter Sleep Pehr As the nights get cooler, here's how to keep your baby snug, safe, and just the right kind of cozy this Autumn. 68 72F: Long sleeve onesie + 1.0 1.5 TOG As the weather warms up (and cools down and warms up again), dressing your baby for sleep can feel a little less predictable. To make spring nights simpler, we've put together an