Portable oxygen tanks are available at any shops in Tibet, and you can buy one when you feel you need them. Our tour buses are also equipped with related facilities that can provide oxygen for emergent events. But we still don’t suggest that you inhale oxygen immediately when you have symptoms of altitude sickness, such as headache, nausea, vomiting and lightheadedness. Otherwise you will forester dependence on those facilities, which will prolong your time to adjust to the environment on this plateau. What’s more, although you would feel better when you use those facilities and equipment, the symptoms will appear again or even become worse once you stop inhaling oxygen.