I'm aware that oxygen is available at Huanglong to treat the effects of altitude sickness. Is it recommended to take preventive medication? My husband did have a bout of altitude sickness in Cuzco more than ten years ago. We think this was caused by rushing between our hotel and travel agent checking on missing luggage. After that we walked the Inca trail and also visited La Paz which is at high altitude and did well. My husband read that people over 50 are less prone to altitude sickness. We are planning to fly to Jiuzhaigou from Chengdu and go to Huanglong before checking in to the Sheraton Jiuzhaigou. As we will be staying at the Sheraton for five nights, would it be more sensible is we visit Huanglong after acclimatising?