The best way to keep your babies warm inside the car is to cover the car seat with the shower cap style Best Car Seat Cover for Winter. Contrary to “footmuffs” that are placed within the seat (i.e. between the baby’s back and rear of the seat) These covers accomplish the job without affecting the mechanics in the vehicle seat -which is essential to ensure the security for your baby. The same reason we do not recommend wearing thick coats or snowsuits while in the car seat. Although it might appear soft and secure however, it’s not. In fact If you take the baby’s coat off and then re-buckle her in the same way and you look around, you’ll see all the gap between her body and harness. The following graphic illustrates this for a toddler. The absence of space is detrimental because it can allow your child’s head to be pushed further forward during an accident (what we refer to as “head exaggeration” in the world of car seat technology). The same concept applies to preschoolers as well as toddlers however it’s more difficult to secure them as they don’t have enough room in the tiny infant car seat.