Luggage and bags:
Small backpack for the stuff you need with you
Clothing/Shoes/Weather Gear: Sun hat, rain poncho
Toiletries and Medical Supplies: Sunscreen--heavy duty kind, and use more of it than you think you need. You burn quickly at that altitude
chapstick or similar lip balm--the dry air takes a toll
WATER - dehydration makes altitude sickness much worse
Miscellaneous: Picture ID of some kind - If you exit the site and want to go back in, you have to show it.
toilet paper - often there isn't any