Seems like a pain in the *** to me. What are you going to do when you are running/in a small bunker/ shooting and reloading. Also you are going to have a piece of tubing that can snag on things.
The best thing I have found, JT goggle fans. I just hit the switch when I want and it sucks the hot air out then I can shut it off. If I'm fogging a lot, like on humid days, I just leave the fan on all game.