Maximum breathing height

What is the greatest height that you can ascend and still be able to breath without O2?

Nobody can breath without oxygen.

Sorry if I was not clear with the OP but I did mean without artificial means or O2 tank.

10,000 feet.

Googled “maxiumum altitude without mask”, second hit.

That is, the Air Force ceiling for no mask.

50,000 for 7 seconds consciousness.

63,000 for your blood to boil.

It’s a little more complicated than that. Lack of oxygen affects night vision quite drastically, so the night flying rule is, or at least used to be, from the ground up. A rule that was commonly ignored.

Mountain climbers have performed their tasks near the top of Everest at 27000 ft. This was before the use of oxygen became common. Even then I think they had oxygen at their staging camp and only made the last “dash” toward the summit without it, and there isn’t any proof that any of them made it.

It seems to me that commercial planes don’t go above 40000 ft. because in case of depressurization even an oxygen mask is ineffective higher than that.

There have been several modern teams that have climbed Everest without O2 tanks. Sort of the “how macho/crazy can you get” crowd.

These are exceptionally fit people. Us regular folk frequently have trouble just hiking at 15k.

Note that there is a large variation among human populations: Andean natives and Tibetans can do work at 10k ft that would flatten most of us at that altitude.

So maybe 10-20k ft for most people if you want to do something, like walk. Add another 10k or so if you are completely inactive. However, time is also a factor. Some people are just predisposed to lung problems at altitude. All it takes for those folk is a day at 15k ft and it’s emergency treatment time.

I don’t know where they got their 10,000 ft figure. I used to attend a summer camp that was at 10,100 feet ASL. Nobody used O[sub]2[/sub] tanks, but we were required by law to rest at least 1 hour in the middle of the day (FOB - flat on bunks/butts/bums).

We also hiked a trail that went at least to 11,000 feet ASL, also without O[sub]2[/sub] tanks.

Uncle Bill’s link is specifically addressing the issue of, “How high can I fly after I’ve just finished scuba diving?”, in other words, addressing the issue of still having nitrogen in your bloodstream from your dive.

And what it actually says is this:

Yes, it’s a good idea to have supplemental oxygen starting at 10,000 feet if you’re flying a billion-dollar Air Force jet. But it doesn’t say “10,000 feet is the highest you can survive without supplemental oxygen”. It says, “10,000 feet is the highest you can go before you could use some more oxygen to help you function more effectively.”

You can survive perfectly fine at 10,000 feet without oxygen–just ask amateur mountain climbers all over the world. How many of these Colorado Fourteeners (peaks over 14,000 feet) require oxygen masks to climb? None, that I can see.

This “Fourteener” website says yeah, you can get altitude sickness, but not that it’s impossible to climb without oxygen–no mention of needing oxygen masks.

And as already mentioned, people have summited Everest without oxygen.

1978, Messner, and again in 1980.

A number of Everest climbers have summited without oxygen since then. Do a Google search for “summit everest without oxygen”.

Australians, 1984.
First woman, 1988.
First Mexican, 1989.

Denis Brown is an industry unto himself.

I don’t ever remembering breaking out the O2 when driving down Trail Ridge Road. Oxygen isn’t listed as essential equipment for climbing a fourteener, either.

Yosemite National Park’s “High Country” (Tuolumne Meadows) is (I believe) 8,000 feet. (Not the same as 10,000 feet, but the best I can do.) I am not exactly at my most fit state (out of shape, more like it) and yet I haven’t noticed any problems when I am visiting the High Country. I might get winded a little quicker than when I am down at a lower altitude, but that’s all.

However, my mom reports that she always needed a few days to adjust to high altitudes. When we were kids, she was always a zombie for the first few days of a family vacation to the mountains. Everyone is different, I guess.

Been there, done that, got the scars…

I’ve climbed three 8,000-meter mountains in Asia, summitting two and failing on the third.* All were above 25,000 feet and all were without bottled O2.

I’ve never climbed Everest, K2 or Kangchenjunga, but I know world-class alpinists that have–all without bottled O2 in most cases. Almost to a man, they have phenomenal VO2 capacity, superb conditioning, and a laser-like focus. Surprisingly, Messner did not possess an elite physiology from this standpoint, but he still managed to summit E. twice sans bottled gas, the second time solo. He also was a better technical climber than 99 percent of the climbers who summit E.

Most people who aren’t acclimatized feeling totally gassed if they exceed 15,000. By 20,000 or so, it’s tough for most people. Even with plenty of acclimatization, the great majority of people, if given the chance to climb one of the major 8’s, couldn’t do it–even with supplemental gas. Their physiologies simply cannot handle it. I talked to one of the world’s most accomplished climbers about this, and he said summiting E. was “exponentially harder” than summiting 28,250-foot K2–all because of the added altitude of about 800 feet. (Yes, it makes a huge distance.)

At high altitude, even the best climbers have a rough go of it, usually having to “stagger” from one rock to the next, and would appear to you as almost hyperventilating. Read some of the chronicles of the world’s greatest climbers on K2. (I’m talking about the best of the best.) Climbing without bottled 02, some are hallucinating, others collapse near the summit and need help getting down.

  • My “failed” attempt was weather related. I’m a strong climber, but definitely not world class. No way.

Well, I know I certainly have no desire to even try…

tsunamisurfer , can you comment on the interaction between latitude and altitude?

I remember hearing that, because the earth’s rotation causes the atmosphere to “bulge” slightly, oxygen levels at a particular altitude are higher near the equator than at the poles. The person I heard this from said that that climbing Kilimanjaro wasn’t as hard as its height might lead you to believe because it was so close to the equator (3 degrees South).

On the other hand, climbing McKinley was harder than it looks because McKinley is so far north (63 degrees North) that the oxygen levels at the summit (20,320 feet) are lower than what someone who had climbed to that altitude in the Himalayas or the Andes might expect.

First, an apology re: the grammatical oversights in my last post. I was in between meetings. I really should get my EA to post for me!

Denali (McKinley) is known as such a tough climb because of the extreme cold, dryness, punishing winds, isolation, and barometric differential. First, an accurate appraisal of climbing is difficult because it’s obviously influenced by subjective considerations. Also, one cannot make blanket assessments on the objective difficulty of a particular mountain since there are multiple routes to the summit. Non-climbers describe the Southeast Route up E. as a joke–totally untrue per Sir Chris Bonnington–whereas other routes, from the Northeast ridge to the Kangshung Face, are quite difficult to nearly impossible.

Because Denali is so much farther north than Everest, some claim that the barometric differential is such that it is Himalayian in difficulty. I’ve heard from one of only 20 (?) Americans who has summited K2 that because it is farther north than E. and because of the technical aspects, it’s a harder climb.

I am scheduled to climb Denali and another 8 in Asia next year. I’ll let you know. What I do know is that you cannot predict who will do well up high. Marathon runners have been known to collapse. Rick Ridgeway (K2, E.) half joked that he couldn’t do 20 pushups, yet thrives at high altitude. I’ve heard from friends who have had minor hallunications on Kilimanjaro, whereas others have called it a walk in the park. Gotta go.

The Canadian Flight training manual I read 14 years ago, stated that for flight about 10,000 for longer than 1 hour (i think) required supplemental oxygen and/or pressurization.

There is a big difference between flying to 20,000 feet in 45 minutes or climbing in 3 - 5 days in terms of the bodies ability to acclimatize.

Also the biggest, and first, danger of the lack of oxygen, when flying, is not passing out, or dying, but suffering from hypoxia, and the euphoric and sense of invulnerability that results.

Remember one climber pealing out, or one hiker falling down a trail above 10000 feet is not as dangerous as a passed out fighter jet pilot.

So “barometric differential” due to latitude is a real, quantifiable phenomenon that would be noticed by an experienced climber?

I’m just trying to confirm this because the person who had told me about it had blown a lot of smoke up my ass previously (see his explanation on the differences in difficulty in climbing Kilimanjaro and Denali as an example of his oversimplification of a multifaceted answer…).

Thanks for your patience.

This is what I’ve been told by world-class climbers in the know. (I’ve also read on the matter, too.) I don’t claim any first-hand expertise on Denali, as I haven’t climbed it yet. Next year, I hope to have somewhat more. That said, plenty of people underestimate Denali. I think the success rate is less than 40 percent–and that’s up the Standard Route. You can bet the average climber on Denali is in better shape than his/her counterpart on, say, Rainier–itself a fairly tough hike/climb. If a storms breaks, it can be a nightmare. Check out Denali’s location on a map–it’s not that far from the Arctic Circle.

BTW, Denali offers an incredible climbing experience with classic routes that leave lifelong imprints on those who climb it. It takes a 3-4 week commitment, and has the highest vertical gain of any mountain in the world. It’s generally regarded as a good Himalyan-type shakedown for E, though some tackle Aconcagua (22,800) instead.

A last thought…

According to one friend who has summitted E. many times, he says that if E. were, say, 3,000 feet higher, it’s likely that no human could reach the summit–bottled gas or no.

It’s as though the Big Man positioned it so that it could be summitted only through the hardest exertions of man.

Bottled gas, of course, is cheating.