2,100 meters is high altitude?!
6,890 feet. Seems “high”.
I find that high altitude starts at 8,000ft for me. For others, 5,000 ft.
There are plenty of people even in the US (all west of the Miss.) who live at over a mile altitude; it's not practical for most of the human race, because of water supply, and even food supply. ("And even the government should know you can't farm at 6,000 feet above sealevel!" -- John Wayne, "McLintock!")
The practical limit of year-round 24/7 residency is something less than 8000 feet; part of the frontier between India and Pakistan has garrisoned observation bunkers, and sudden loss of ability to breathe, leading to immediate evac by air, and sometimes a quick demise, isn't all that uncommon.
Whoops, the India-Pakistan frontier is the Siachen Glacier, which is a good deal higher than that — 2.5 to 3 times higher than that, which is wtf up there. To put it into perspective, if memory serves (that’ll be the day), per the FAA pilots of hot air balloons have to be on oxygen at 8000, and all passengers have to be on oxygen at 13000. The Paki bases are around 7000 *meters* and the Indian bases at or above 8000. Holy crap.
To probably 85% or more of the population of the United States, 6400 ft is high altitude...Just because YOU live at 5600 ft doesn’t mean everyone thinks it’s not high altitude....