It’s all hype, isn’t it? After all, how can there be anything wrong with strapping your child into a car seat with her coat on? It must just be because some parents don’t get the straps just right—like you do—when they strap their kids in over a bulky coat. Or that it only applies to those big puffer coats. Right?

Wrong. According to Kelly Klasek, lead instructor of community education at St. Louis Children’s Hospital, it is never okay to secure a child wearing a coat into a car seat. In fact, any car seat manufacturer or certified child passenger safety technician would agree on this point. “In a crash, the car seat is meant to, and will, move within the vehicle to absorb the energy of the crash,” Klasek explains. “The primary safety feature of the harness is to keep a child secured in the seat so he rides with the seat but does not move within his harness. The force of a crash will cause the thickness of the coat to flatten, ensuring that the child will move within the harness and increasing the chance for injury. By putting a child in a coat before securing the harness, you compromise the primary safety feature of the harness.”

You can visualize this by strapping your child into her car seat with her coat on and pulling the straps snug, then unbuckling her, taking her coat off, and rebuckling the car seat. See the slack in the straps? When your child’s coat flattens during a crash, that’s how loose the straps will actually become. If you wouldn’t buckle your child in with the straps that loosely, you shouldn’t let your child’s wear her coat in the car seat. Consider this “the coat test,” and use it to figure out whether your child’s outer layers are safe for use in the car seat.

Tips for Parents

Still, when it’s 10 degrees outside, you’re not likely to bring your child outside without any coat at all. What can parents do to stick to this rule without worrying about their kids turning into ice cubes? Here are some tips that might work for you:

  • Cover them up. On a cold but not freezing day, you might want to replace your child’s coat with a blanket once you get to the car. Your child can keep the blanket on while the car warms up and kick it off when she’s warm enough.
  • Try a poncho. If you sew, you can make your own car seat poncho that goes over the straps in the front and over the car seat in the back. Car seat ponchos are also available online.
  • Layer. While even the thinnest winter coats are unsafe to wear under a car seat’s straps, you can dress your child in a fleece jacket or a sweatshirt, covered by a coat. In the car, just take off the coat but keep on the thinner layer underneath to take the chill off until the car warms up.
  • Don’t ditch the coat. Instead, after buckling in your child, put your child’s arms through the sleeves and let her wear the coat backwards.
  • Use car seat covers for infant seats. Just make sure to choose the kind that only have material over the harness, rather than those that go under the baby. Although both of these are sold in most baby stores, the latter can interfere with the harness, and thereby the safety of the car seat.
  • If your child’s thin winter coat fails the coat test, but not by too much, try this technique. Unzip your child’s coat, and secure the straps snugly with the coat pulled away from your child’s body on each side so that the straps are not over the front of the coat at all. (This may not work well with coats that have hoods, since the material will bunch up around your child’s shoulders, so remove the hood if possible.) Then rezip the coat over the harness straps. Use the coat test to see whether this technique leaves the straps tight enough to be safe for your child. If you’re absolutely sure that your child’s coat passes the test with this technique, it’s better than leaving the coat zipped under the harness. (Note that Klasek prefers that parents do not use this option, since it can be difficult to tell whether a coat is too bulky to pass the test.)

At the end of the day, no one will pretend that it’s not easier to just strap your child in with her coat on. But if you believe in the importance of using a car seat in the car, you should make sure that you’re not sabotaging the main safety feature of the car seat. “Over the last several decades, we have learned a great deal about how to protect our children,” says Klasek. “Cabinet locks and outlet plugs and safety gates get in our way, but we all use them, because we know the benefit to our children's safety far outweighs the inconvenience. And it's habit now. Those things are all expected. Safety seats are no different. Yes, it's frustrating and time consuming to juggle kids and diaper bags and keys and coats for a short drive to the store. But the fact is, most crashes happen close to home. Improper use of a car seat harness, including keeping a coat on when securing the harness, offers a false sense of security.”

So next time you go out on a cold winter day, find an alternative to squeezing your child’s winter coat into the harness. Your child’s safety is at stake.