When you feel like you're tightening up take it slower or stop for a minute or two, try to avoid hiking features. Take your inhaler on the first chair or in the parking lot, try not to push yourself that way. Make usre you breath deep into your stomach, I used to tighten up and breath less when I skiied and it made it 10x worse. After all unless you're skiing whistler or Colorado/Utah you don't usually ski that much continuously unless you have a really big hill, So take advantage of lift rides and cat tracks when you can chill.
Not much to say about touring other than pace yourself
I find that the more I run or bike in the cold the better I am with dealing with it when I ski. Your warm weather fitness level doesn't mean shit.