I cannot urge you enough to start conditioning as much as you can now if you have not already started. Some people make the transition beter than others but being in as good as shape as you can will help. High altitude is a tricky thing, I use to take people on 14'ers here in Colorado and there is really no way of knowing who will get altitude sickness and who won't but you need to read up a little and be able to recognize the symptoms and how to treat it. I have even known some to get high altitude pulmonary edema (spelling?) which is scary but rare. One thing to make sure you do is stay hydrated. You will be huffing and puffing a little but the views alone are usually worth it. P.S. try to get to reputable site like web md or something similar as their are a lot of wivestales regarding treatment of altitude sickness. Have fun!!!