On Kilimanjaro, most of your personal gear will be carried by hardworking porters. As climbers begin their trek in the morning, the porters stay behind to break down the tents and clean the campsite. Then, the porters proceed ahead of the climbers at a faster rate, beating the climbers to the next campsite to set up, prepare meals and boil water. Therefore, climbers will often not see their porters again until they have reached their overnight destination and thus will not have access to the gear that the porters have transported until then.
Climbers are expected to prepare their own day packs and to place all other items into a duffel bag for the porters. As far as what goes into the day pack, it depends on what you may need during the day. This typically includes rain gear, some extra layers of clothing in case the temperature drops, and clothing accessories. Additionally, climbers should carry sunscreen, insect repellent (at lower altitudes), first aid kit, toilet paper, snacks and water. The general rule is only carry what reasonably can be expected to be needed. For instance, you do not need to carry fleece, insulated jackets, and gloves in the rainforest. The sleeping bag and pad should not be carried, and probably would not fit, in your day pack.
To pack your day pack efficiently, you should use plastic bags or dry bags to separate items based on categories. For example, small bottles such as prescriptions, sunscreen, lip balm and hand sanitizer should be secured in a zip-lock type bag. Extra layers of clothing should also be put into larger bags. Paperwork, such as your passport and insurance documents into another bag. Heavier items should be placed close to the midpoint of your back to keep your center of gravity in-line with your spine. Placing heavy items near the top, bottom, left, right or rear of your day pack will cause you to lean forward, back, or to the side. If your day pack has compression straps, tighten them so that your items do not move around as you walk. Lastly, be consistent as to where you store your items (main compartment, side pockets, pant pockets, etc.), so that you do not fumble for your items when needed. A medium sized backpack, with the capacity of about 1,800 cubic inches (30 liters), is appropriate.
Sea to Summit eVac Dry Sack
Gregory Z30 Pack