What to wear baby in car seat during winter? WINTER IS COMING And if you live in a cold climate, and have a child in a car seat, it is imperative that you know how to keep your child warm and Bundle Up, Baby! A Guide to Safely Layering Up in the Car SAVE & SHARE! Winter is coming so we wanted to share some important information!, Winter clothing such as coats, thick jackets and snowsuits should not be worn in the car seats , For many Winter Car Seat Solutions