What is the meaning of gradual step-by-step tourism?

Step-by-step tourism is a kind of tourism mode developed for tourists to gradually adapt to the plateau environment. According to the relevant public information, the average altitude in Tibet is more than 4, meters, and tourists are prone to altitude sickness, which affects the development of tourism in the Qinghai-Tibet Plateau. Step-by-step tourism is a tourism model developed to let tourists gradually adapt to the plateau environment.