Altitude sickness is the main cause of fatalities on Mount Kilimanjaro. Therefore, many operators have oxygen available to treat climbers who have developed moderate or severe altitude sickness.
Upon request, Ultimate Kilimanjaro will carry oxygen for emergency purposes only, to treat a stricken climber in conjunction with immediate descent.
However, there are some operators who advertise the use of a “personal oxygen system” to assist climbers on Mount Kilimanjaro. Besides the fact that you would look more like a hospital patient than a mountain trekker, there are serious reasons why using oxygen in this manner is NOT advised.
When you develop symptoms of moderate or severe altitude sickness, it is not because the body is trying to make it unpleasant for you without merit. It is because the body recognizes that you are unable to function at the current altitude, and does not want you to climb any higher. Your body is telling you– DESCEND NOW. Not listening to the body is how most people get into trouble on the mountain.
By using supplemental oxygen, you have effectively stopped your body’s attempts at acclimatization by raising the oxygen content of the air you breathe. Using oxygen to climb ignores your body’s clear message to descend. And while your body was unable to acclimatize to the current altitude, you have made things even worse by climbing even higher. It is dangerous situation.
Lastly, what is point of climbing Kilimanjaro with supplemental oxygen? The difficulty of Kilimanjaro lies with its altitude. As a trek, it is not difficult by hiking standards, if you remove the challenge of high altitude. I guess some people climb Kilimanjaro just to say they did it, regardless of the manner in which it was done. But it is not much of an achievement if you put the mountain at sea level.
The bottom line is that supplemental oxygen is potentially dangerous when used to climb higher, is wholly unnecessary on Kilimanjaro, and is against the spirit and challenge of climbing Kilimanjaro.