Chapter 11 · Forest and mountains
Altitude sickness
The Centers for Disease Control and Prevention (CDC) note that the risk begins at sleeping altitudes of around 8,000 ft (2,450 m), sometimes lower. It does not affect you in lowland areas, but it does on trips to the Rocky Mountains, Colorado, New Mexico, central Mexico, or the Andes.
| Condition | Signs | What to do |
|---|---|---|
| Acute mountain sickness (AMS) | Headache plus at least one of: loss of appetite, nausea or vomiting, dizziness, fatigue. It appears 2 to 12 hours after ascending, often after the first night. | Do not go higher. Rest and drink fluids. If it does not improve or gets worse, descend. Descending at least 1,000 ft (300 m) brings quick improvement. |
| High-altitude cerebral edema (HACE) | Confusion, drowsiness, clumsy walking (cannot walk a straight line heel to toe). It can progress to coma within 24 hours. | Emergency. Descend immediately, accompanied. Oxygen if available. Call for rescue. |
| High-altitude pulmonary edema (HAPE) | At first a cough, shortness of breath with exertion beyond normal, poor performance. Later, shortness of breath at rest, noisy breathing, bloody sputum. | Emergency. Descend immediately with as little exertion as possible for the victim. Oxygen if available. |
Prevention
- Avoid going up in a single day to sleep above 9,000 ft (2,750 m).
- Above 9,800 ft (3,000 m), do not increase your sleeping altitude by more than 1,650 ft (500 m) per day.
- Add an extra night of acclimatization for every 3,300 ft (1,000 m) of sleeping altitude you gain.
- "Climb high, sleep low": you can make excursions to higher altitude during the day if you return to sleep lower.
- Avoid alcohol the first nights. Prescription preventive medications exist; consult your doctor before the trip.
