Heh, brings back some memories.
Last year at this time I was staying in a village on a lake in Peru at 3812m. Nasty headache, and exhausting just walking around. Took some altitude medication which helped but had the side effect of making my skin feel like it was vibrating off. Then of course the harsh sun fries the skin given a chance. First time I ever saw ads for 100 sunscreen. Throw in some stomach trouble and it's like, what am I doing here?!
Got up to 4400m at the highest and even plants just seemed to give up.
Our Rockies are pretty low in comparison. Banff is at a puny 1383m, Kicking horse pass is only 1627m. The top of the highest mountain in Alberta is only 3750. That's where those South American plateaus start, people go about their lives, fish, farm, etc. Crazy.