The most important thing is to hydrate and take it easy at first. I lived in the Andes mountains for a work project, the elevation we stayed at was bout 14,800 feet but we did get up to about 16,080 feet in elevation. When I first got up there I was sick as a dog, after about 3 days I got acclimated to it. Your body also burns a lot of calories at that elevation, I lost a lot of weight. Ibuprofen is your friend. Some people take a small oxygen bottle up, if they start to get a headache, about 10 minutes on the oxygen helps a lot. Be careful.
