> acclimation to higher altitudes

Is this really much of an issue? I'm sure altitude sickness can occur at some places like breckenridge, but even there most people seem to adjust within a day or two. Altitude over 4km is a different story, but don't think there's a single resort in the world at that height.

edit : ok I was wrong, there are at least 5 resorts with a peak over 4km across China, India and Bolivia. still think those are outliers :D