I was looking into possibly visiting Lhasa, and I see nothing but horror stories regarding people getting altitude sickness there. Lhasa is around 12,000ft elevation. In the past, I have competed in athletics in Denver (5,280ft) and Copper Mountain, CO (~10kft elevation) with no difficulty. Given that I was able to play sports at 10k feet, should I be at all worried about visiting Lhasa for tourism?