What to do!?

So I'm not sure what to do. Every time I pick up my son he smells like smoke! We ask him about it and he says that he does not like the smell of smoke, but he is only 6 and does not feel like he can say anything. We have tried time and time again to tell him to ask the people to stop, but it continues to be a problem. It's so frustrating having to make him take a bath when I pick him up and having to wash all his clothes, sometimes twice to get the smell out. I just don't understand how you can do that to kids and not care one bit about what it is doing to them. My father has smoked his whole life. The thing is, I can't tell you one time that I was a kid where he smoked in the house, or smoked in the car, or anywhere else that would keep us closed in with the smoke. Just don't understand how hard it is to go outside for 5 min and let the kids have clean air to breath inside!!