If you are so ill that you have to wear a portable oxygen tank and can barely walk two feet without having to sit down, you might want to DISCONTINUE smoking. (It's a dead giveaway that you still smoke when your entire body reeks so badly of cigarette stench that it makes the people around you cough.)
HELLLOOOOOOO...YOU'RE ON A PORTABLE OXYGEN TANK!
I mean, this is just my opinion but...
