Coats and Car Seats PA Promise for Children If you fasten your child in their car seat with their winter coat on, it could potentially be dangerous. The harness is not tight enough to prevent them from slipping out during Winter Car Seat Safety: How to Keep Your Kids Safe AND Warm TheMonarchMommy What's the Deal with Winter Coats in Car Seats? 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 Bundle Up, Baby! A Guide to Safely Layering Up in the Car