There are currently nine states where it's illegal to smoke in a car with a minor, which are Arkansas, California, Illinois, Louisiana, Maine, Oregon, Utah, Vermont, and Virginia. Guam, Northern Mariana Islands, and Puerto Rico are US territories that also prohibit this. Additionally, check your local laws as some states may be testing a new law that prohibits this. In any case, it's very dangerous for your child to inhale secondhand smoke and we recommend you don't do this regardless of where you are. Child Protective Services may get involved.