How to Dress for High Altitude

Dress in three distinct layers to manage extreme temperature swings and moisture. Prioritize synthetic or wool fabrics over cotton to keep your body temperature stable when the air gets thin and cold.

1. Select a moisture-wicking base layer. Wear a thin merino wool or synthetic long-sleeve top. Avoid cotton, as it traps sweat and will chill you immediately once you stop moving.
2. Add an insulating mid-layer. Use a fleece or a lightweight down 'puffy' jacket. This layer traps your body heat. Ensure it is easy to remove if you start sweating during a steep climb.
3. Top with a windproof shell. High altitudes are consistently windy. A technical shell with a hood prevents wind-chill from stripping away the heat your mid-layer is trying to trap.
4. Protect your extremities. The sun is significantly stronger at high altitudes. Wear a brimmed hat and polarized sunglasses to prevent UV-induced snow blindness or headaches.

Why can't I just wear a heavy parka?

You will overheat during exertion and freeze when you stop. Layering allows you to regulate your temperature in real-time.

Is cotton really that bad?

Yes. At altitude, it stays damp from sweat and loses all insulating properties. If you get wet at 3,000+ meters, you are at high risk for hypothermia.