In short, no. Snowsuits are not safe to wear in a car seat. A thin fleece outer layer should be fine, but a puffy snowsuits will prevent the car seat straps from being truly snug around your baby. Per the American Academy of Pediatrics, the fluffy layers of clothing can get squashed down immediately by the impact of a car crash, leaving the straps loose and your baby at risk for being flung from their car seat. Scary, we know. The AAP advises dressing babies in several layers of thin, moisture-wicking clothing (this can include hats and mittens) for cold car rides, and adding a blanket on top if needed, once baby is snugly strapped in. You can then put your baby in their bunting or snowsuit once you arrive at your destination. Additionally, wearing a snowsuit or too many heavy layers while in the car seat can actually put your baby in danger of overheating. Again, babies don't thermoregulate very well yet, so they can easily get too hot if overdressed. If you have any questions about your baby and car seat safety, give your pediatrician a call - they're experts at keeping babies safe and healthy.