I wanted to post a little bit about my experience with being "at altitude", because many people (including myself) expressed their worries to me, before the trip, about how it would affect me.
(Okay I just realized that that last sentence implies that I expressed the worries to myself, which basically is true; however, it sounds strange.)
First, the fun stuff:
- Sometime during the morning of the second day of the train ride, after we left Golmud, we heard a loud popping sound. We all immediately looked around to see what we'd dropped, but there was nothing on the ground that wasn't supposed to be there. Later in the day, we realized what had happened: one of Charles's Doritos bags had been expanding and expanding until the air pressure inside the bag became too much for the flimsy material of which the bag was constructed. I spent a good five minutes laughing about that. Other snack bags became puffed up like blowfish, but none of the other ones popped.
- At altitude, sodas and beer would fizz immediately upon opening them, no matter how steadily you held them. And if you stuck a straw in the can or bottle, the liquid would immediately start running up the straw and out onto the table. It wasn't a whole lot, just drops really, but it was noticeable, like some invisible person was sucking on the straw. It was kind of freaky to see such self-possessed liquid, like the blood that splashes off the elevator in The Shining, or that oil shit from the X-Files. Plus, it was messy. So although it was hilarious, we didn't use straws.
- The reverse also happened. When we were in Lhasa packing to go home, I sealed a tupperware container, which had originally carried snacks for the train, with some breakable/smushable souveneirs. When I tried to open the container back at sea level in Shanghai, it was more difficult than normal to pull the lid off. The extremely low air pressure inside the case vs. the higher air pressure outside had created a low-quality vacuum inside the container. Or, to return to a previous similie, it was like someone on the inside of the container sucking inwards (as if with a straw) and pulling the lid back onto the container. That's my understanding anyway. Yay physics!
Now the not-so-fun stuff:
- At altitude, we definitely noticed difficulty breathing. Not extreme difficulty like, oh my gosh, I'm suffocating -- but heavier-than-normal breathing after, say, walking up a flight of stairs, walking around the city doing extended tourism, or walking 10 minutes, laden with luggage, from the train station to our rented Land Cruiser. The first night in Lhasa, Dan and I climbed the 2 flights of stairs to our hotel room just to see what it'd be like. It was fine, but definitely more difficult than it should have been.
- It was easier than ever to get pins and needles in a foot or leg. It happened much more quickly than at sea level. I had to watch even for draping my arm backwards over a chair or anything else that would reduce oxygen flow to a limb. Again, it wasn't incapacitating or horrible, but noticeable and therefore interesting.
- Headaches. Oooh boy that was not fun. I was fine and dandy in Lhasa. But once we set out for Shigatse, which is 1200m higher than Lhasa, I began to get small recurring headaches, especially when we ascended Mt. Gangbala (to see Yamdrok-Tso Lake) and other heights along the road. We hit heights of 5000m on that road before descending to 4700 at Shigatse. I think that the relatively rapid (within 5 hours) string of ascents and descents did not help, either. And it only got worse the next two days when we went to and from Everest. I basically had a headache, and was freezing cold, for two whole days. It was not pleasant -- especially when you throw in mediocre food, the fact that you're sitting in a car for 5 hours a day, and stench-filled open-pit bathrooms -- but like I said, I managed okay. Others in our group did not. In addition to the headaches, some experienced nausea, and more difficulty breathing, and one of them tossed their cookies right outside our tent at Base Camp. I'm really happy that none of that happened to me (and also that we bought some headache medicine in Lhasa), but I felt really bad for them. They spent most of those two days sleeping and having difficulty breathing. They'd wake up at tourist/scenic spots, but other than that, they were just really lethargic. It looked shitty, and I'm sure they did not enjoy those two days, even though those days included Everest. But on the bright side they survived intact :-) So the lesson here is that altitude sickness affects everyone differently. One of our group didn't even have a single headache. So our group ran the gamut from no effect to shitty effects, heh. Luckily everything cleared up on the second-to-last day driving from Shigatse back to Lhasa. I never thought we'd be so happy to see 3700m :-)