Jiuzhaigou mouth on the northern edge is only 2000 meters above sea level, and the peaks in the middle are all over 4000 meters, and the southern edge is over 4500 meters.

When the altitude reaches about 2700 meters, altitude sickness will appear at about 3600 meters in Lhasa. Methods to prevent altitude sickness: 1) Take Ogilvy tablets, American ginseng, glucose solution, etc. Prevent altitude sickness one week in advance. Moderate oxygen inhalation for severe altitude sickness. 2) When you first enter the plateau, you should move slowly, not fast. Don't walk too fast, let alone do manual work while running. It is best to have a thorough rest for half a day.