A little bit of acclimatisation or no acclimatisation at all?

Question

This summer I'm planning to mount my first 4000 m mountain in Switzerland. So far I only got around 3300 meters while hiking and had no problems. However 4000 meter an above is definitively a different category.

Since my goal requires a little bit of experience how to cross a glacier, I will do this in a guided tour, since it is my first time. There are basically two opportunities:

1) On day 1 arrive around lunch time on a mountain hut located around 3600 m. Do some hikes in the near surrounding and stay there over night to acclimatisation a little bit. On day 2 in the early morning go up to the mountain (4050m) and descend to 500m and go home.

2) Arrive early on the first day, go up to the mountain and in only a few hours back to 500m. This would include a visit of approximately 5 hours on altitudes higher than 3000m.

Now if heard, that if you're staying only a very short amount of time on high altitudes (a few hours) you probably won't get any altitude problems. That would justify to choose option 2. On the other hand, acclimatisation isn't a bad thing, but is less than 24 hours as planned in option 1 reasonable?

Answer 1

Either option is acceptable, particularly since you aren't going very high. There are rare instances where people get Acute Mountain Sickness (AMS) or worse even at relatively low altitudes, and these are more common when there is no acclimatization. However, it is very rare for such problems to suddenly arise and not be fixable (through rapid descent). Each option has advantages and disadvantages.

Option 1:

• More time at the mountain (more relaxed)
• Some acclimatization benefit
• Takes longer
• Possible sleepless night may mean a rough summit day

Option 2:

• Quick and easy
• No acclimatization benefit
• One big push might be too much for some people
• No acclimatization increases risks for AMS, headaches, fatigue, etc.

In terms of comfort, this will depend on the person. Option 1 might include a sleepless or restless night, since it is the first night after rising 3100m, which would be very uncomfortable. On the other hand, if you sleep well, the extra mild exertion and time at altitude will help somewhat. Option 2 might be less comfortable due to the hard work at high elevations with no acclimatization. Again, though, the short timeline means that if you are otherwise healthy, rested, and hydrated, there is a good chance you will be rather comfortable aside from having to push a little harder.

Others might lean one way or the other, but honestly I'd focus on staying strong and healthy, and taking the most convenient option.

Answer 2

I think Greg's answer is excellent, but I'd add the following. It's true that there's a delay before altitude sickness sets in - this is what makes going up to a 4000 meter peak on your second day possible. However, should conditions on the top be bad, and you end up staying up there, you are at some risk of altitude sickness. For example, if you twist your ankle on the top and going down becomes a much slower affair. I'd still say that both options are doable and not particularly risky, even if it wasn't a guided tour, but it's worth mentioning.

Personally, I'd prefer the first option, but that's me.

Answer 3

There isn't much difference in the two "acclimatization" options. In neither option do you get more than a start on acclimatization. In both options, you serve notice on your body to get ready.

Option 2 might be "safer" in that your chances for a good night's sleep and a good dinner are better at the hotel than the hut. Thus, you might start the climb more rested. But Option 1 might be "safer" in that whatever problems you might have, might manifest themselves at the level of the hut, or soon thereafter.

So, my answer is go with what you want to get out of the total experience. Is the camaraderie at the hut important? Is spending a night at 11,800 feet, far from the tourist crowd at the base of the mountain important? (Is sleeping outside the hut under the stars possible?)

Assuming you are in good shape, and knowing that you have had no trouble at 10,800, and knowing that you will be with a (presumably) reputable guide, and assuming that if you feel awful you will be sensible, then flip a coin or go with your gut. Nothing is certain; you could get run over tomorrow.

We had a similar experience 10 years ago in Chile. We were staying at San Pedro de Atacama (about 8,500 feet) and went to the Tatio geysers (about 13,000 feet) in the morning. Then we walked up Cerro Tocco (about 18,400 feet) in the afternoon and had no problems, not even mild headaches. (But what was OK for us might not be OK for someone else, and vice versa.)