Watch Altitude Sickness Symptoms
Pema explains that when he’s the guide for a hiking group he watches everyone for symptoms of high altitude sickness. If someone is showing symptoms, he makes sure it's not from some other pre-existing condition. If they show symptoms he arranges to bring them to a lower elevation. Symptoms he watches for are if they are very tired (because the hiking they normally is not that strenuous), unable to talk, headache, dizzy, aching joints. He would ask, "Do you have this before? Do you usually take medication for it?" Once Pema determines that there was trouble he would assign a Sherpa to take the hiker down to a lodge where it's quiet so they could rest.
Pema would ask, "Any people seem like they're not doing well?" and then follow up for more details. He would check to see if anyone was not enjoying the hike, walking slowly, or getting dizzy; all subtle signs. If one of the hikers must go back to a lodge and takes more than a day or two the group will want to continue without them. Maybe the person who had altitude trouble can then hang out in the area or go a little higher, but they will have to wait for the group to come back through and take them to Kathmandu.
or severe cases Pema will use a Gamow bag. It’s a clear plastic bag, about 3 feet in diameter and over 7 feet long. When someone is getting very bad altitude sickness, like they can't talk and they're very confused, he will have them lie down inside bag, seal it off, and operate a foot pump to over-pressurize with air. It helps them feel like they're at a lower altitude and they'll soon feel better (within 2 to 4 hours). On the expedition Pema prefers to carry at least one of those. It costs about $250 to rent one of those for a trek. It folds up and fits in a backpack.