While participants are strongly encouraged to pack as lightly as possible, dressing in layers is important when traveling in Peru. At the high altitudes of Cusco, Machu Picchu, and Lake Titicaca, it can be fairly warm during the day, with a strong sun, yet the temperature can plummet at night to freezing.
Light wool is a good choice to wear against your skin as it naturally helps to regulate your body temperature - keeping you warm in the cold and wicking away moisture when it's hot - and it doesn't retain odors, even after prolonged wear.
Rain gear: waterproof or quick-drying pants; a waterproof jacket or poncho
A sturdy pair of broken-in hiking boots (or waterproof trekking shoes)
Warm coat or fleece layers, hat and gloves (for chilly to cold temperatures)
Walking stick (if needed or preferred)
Day pack (so you can keep another layer of clothing or your rain gear with you at all time)
Overnight bag (see note below)
Bandana (for dusty environments)
Passport and color photocopies of your passport
Photocopies of credit cards
ATM card with a 4-digit PIN for international use
Journal and pens
Plug adapters (and converter, if needed)
Travel alarm clock
Toilet paper or tissues
Any prescription, in its original container, or over-the-counter medication (stored in your carry-on bag)
Note: When we travel to Machu Picchu you can only bring an overnight bag with you. All large suitcases will be left in Urubamba and picked up on August 26th as we head to Cusco.