Altitude sickness is the unfortunate side effect that is essentially the result of pushing your body to places it was never designed to be.
While there are some scattered cultures that have made their homes high in the mountains throughout history, for the most part, the human body is ill-equipped to handle the thin atmosphere and low oxygen levels to be found in higher altitudes.
Luckily, the human body is very adept at adapting to changes; given enough time, the body can become more efficient at transporting oxygen throughout the bloodstream.
However, if you find yourself in a bug out situation or mountain survival situation and find yourself or your companions suffering from altitude sickness, you may not have time to wait.
In that case, you may have to resort to the methods on the next page.