Bangkok airpollution

So I have to go to Bangkok for a few days tower my friend who is flying in from Norway to come meet me. I’ll have to spend 3 days in Bangkok and I’m getting a bit nervous because of all the air pollution. Would it not be smart to walk around outside even with a face mask? Should I stick to being in the room only? Or is it okay to go to restaurants and bars that are indoor? I’m Norwegian and we never have problems with air pollution so this is brand new to me…