(WENY) -- As temperatures start to dip in New York, parents are dressing their kids in puffer vests and shopping for new winter coats. This could be putting thousands of kids’ lives at risk.

According to the National Highway Traffic Safety Administration, nearly 90% of parents are using car seats incorrectly and putting children’s lives at risk. One mistake is letting kids wear puffy vests and coats in their car seat which makes safety harnesses ineffective. 

"The puffiness of the coat underneath the harness like you see here adds about three to five inches of slack underneath the harness and when your in a crash the course of the crash is going to compress all that puffy fabric leaving all that space and research has shown that as little as six millimeters of extra foreign movement creates brain damage and spine injuries in a child so that can be the difference between a trip to the hospital after a car crash or just go home," says child Passenger Safety Technician Dahlia Rizk. 

Its important for parents to know the importance behind the harness for your children and the safety risks behind it.