Why shouldn't I bring cotton?

Cotton absorbs moisture and dries slowly. At high altitudes, sweat or light precipitation will freeze against your skin, significantly increasing your risk of hypothermia.

Do I need special equipment for altitude sickness?

Pack a pulse oximeter ($20-$40) to monitor your blood oxygen levels. If you are prone to sickness, consult your doctor about prescription acetazolamide before you leave.

How to Pack for High-Altitude Travel

Pack in layers using moisture-wicking synthetic or wool fabrics, and prioritize sun protection and hydration gear. Because oxygen levels drop as you climb, your gear must focus on thermal regulation and physical comfort rather than heavy bulk.

Layer for variable temperatures. Follow the three-layer rule: a moisture-wicking base layer, an insulating mid-layer (fleece or down), and a windproof/waterproof outer shell. Temperatures can drop 3-5 degrees Fahrenheit for every 1,000 feet of elevation gain.
Prepare for extreme UV exposure. Pack high-SPF sunscreen (at least SPF 50), polarized sunglasses with UV400 protection, and a brimmed hat. UV radiation increases by roughly 10% for every 1,000 feet of elevation.
Choose the right footwear. Bring broken-in, waterproof hiking boots with ankle support. At high altitudes, trails are often rocky or snowy; ensure your boots provide solid traction and fit comfortably with thick wool socks.
Optimize for oxygen efficiency. Bring a hydration bladder that allows you to drink without stopping. Dehydration is the fastest way to trigger altitude sickness; aim to drink 3-4 liters of water per day.

Why shouldn't I bring cotton?: Cotton absorbs moisture and dries slowly. At high altitudes, sweat or light precipitation will freeze against your skin, significantly increasing your risk of hypothermia.
Do I need special equipment for altitude sickness?: Pack a pulse oximeter ($20-$40) to monitor your blood oxygen levels. If you are prone to sickness, consult your doctor about prescription acetazolamide before you leave.