(HealthDay News) -- The low oxygen levels found at a high altitude can make travelers feel sick, says the U.S. Centers for Disease Control and Prevention.
The best way to avoid sickness is to ascend gradually. But if you have to ascend quickly, you can take medicine to help prevent problems.
The CDC urges those traveling to an altitude above 8,000 feet to avoid alcohol and heavy exercise for the first 48 hours. If you feel unwell, and symptoms worsen while resting, you must descend or risk serious illness.