Keys to preventing acute mountain sickness include:
Climb the mountain gradually. Gradual ascent is the most important factor in preventing acute mountain sickness.
Stop for a day or two of rest for every 2000 feet (600 meters) of climb above 8000 feet (2400 meters).
Sleep at a lower altitude when possible.
Make sure that you have the ability to rapidly descend if needed.
Learn how to recognize early symptoms of mountain sickness.
If you are traveling above 9840 feet (3000 meters), you should carry enough oxygen for several days.
If you plan on climbing quickly, or climbing to a high altitude, ask your provider about medicines that may help.