Packing for High Altitude in the Andes

Pack for rapid temperature swings by using a four-layer system and prioritize high-SPF protection and hydration gear. Because oxygen is thin and the sun is intense, your goal is to regulate body heat efficiently without overloading your pack.

  1. Adopt the four-layer rule. Bring a moisture-wicking synthetic or merino wool base layer, a lightweight fleece mid-layer, a down or synthetic insulated jacket for cold nights, and a high-quality windproof/waterproof outer shell.
  2. Protect against high-UV exposure. Pack polarized sunglasses with high UV protection and a wide-brimmed hat. The atmosphere at 3,000+ meters is thinner, meaning you can sunburn in under 20 minutes.
  3. Manage hydration gear. Carry a 2-liter hydration bladder for your daypack and a separate 1-liter insulated metal bottle for evening hotel use. Hydration is the single best way to mitigate altitude sickness symptoms.
  4. Prepare your medical kit. Include Ibuprofen for altitude headaches, electrolyte packets (like Liquid I.V.), and lip balm with SPF 30+. Speak to your doctor about Acetazolamide (Diamox) if you are traveling above 2,500 meters quickly.
Do I really need a heavy down jacket?
Yes, if you are traveling above 3,500 meters. Temperatures can drop below freezing at night, even in the middle of a sunny day.
Can I just buy gear when I arrive in Cusco or La Paz?
You can find alpaca wool items easily, but technical gear like high-SPF sunblock, specific medications, and reliable windbreakers are often more expensive or harder to find in local markets. Bring your core technical kit from home.