Most travelers can adjust to elevations below 8,000 feet with only minor headaches, treatable with over-the-counter medications. Even individuals in the best of shape, however, can suffer from worse symptoms, including fatigue, dizziness, and sleep disruption. Overexertion increases the odds of experiencing altitude sickness, so take things slowly, stay hydrated, and limit alcohol consumption. When ascending above 8,000 feet, where the air becomes markedly thinner, limit your climb to 1,000 feet per day. Prescription medications such as Diamox and dexamethasone can lessen the effects of altitude sickness. As always, consult your doctor before taking any medication.