Fair and poor air quality damages lung tissue. Over days and weeks of exposure, your lungs will have to suffer...some...maybe quite a bit. If you have pre-existing impediments to health, especially to lung tissue, it would of course be cumulative or additive, and perhaps put you over the edge enough that you notice a distinct and unwelcome change. Unfortunately, damaged or diseased lung tissue is already at a deficit for gas exchange which, after all, is what the blood and alveoli are meant to do. Pure and directly delivered oxygen will probably help, although the apparatus might hinder enjoyment and freedom of movement, or might possibly put you at risk for injury. If it's a solution for you, why not give it a trial prior to any ski excursions. Hike and bike with oxygen delivery and see how it goes. Get used to wearing it and dealing with its effects on your exercise and recreation. If you can handle it all, then......