Pack the minimum wherever you travel! Planing a trip to Tibet is just the same as in any other places. But remember Tibet is on the roof of the world and most part of it is remote area. The things to pack should be in your consideration beforehand.
Bags: A large backpack and a smaller one. The smaller one can be used for daily activities and can also be put into the big one when necessary. And a waist pack to put property and important documents.
Cold-proof clothes: The temperatures change greatly on the altiplano. In the north part of Tibet, people wear thick coats all year round (including July and August which are the hottest months in most of the areas in China). The highest temperature is 4-5 degrees centigrade in northern Tibet. It also snows in July and August. In Lhasa, the temperature in July arrives at 30 degrees centigrade at daytime, but falls to 10 degrees centigrade at night. Sometimes it will snow or sleet at night, so you'd better take some down garments (those with hats will better), woolen sweaters, warm gloves, warm and wind-proof shoes and socks. Wearing several layers of clothing that can be easily added or removed is the wise choice since temperatures may vary greatly within a single day. A down coat is necessary for those who are traveling beyond Lhasa and Shigatse into more remote areas such as the Everest Camp. A windbreaker plus a sweater will work nicely for strolling around Lhasa in summer. During the peak tourism season, frequent rainfall makes waterproof clothing and raingear absolute necessities. Other essentials to pack include four or five pairs of cotton or woolen underwear, four or five pairs of woolen socks, long sleeve cotton or lightweight wool shirts and T-shirts. Women should avoid skirts or dresses.
Shoes: It is very important to have a strong comfortable pair of boots. Lightweight boots are fine, but Tibet can be wet and we will do extensive walking, so make sure your shoes fit well and are suitable for cold and puddles. You should also have a pair of comfortable and tough sandals.
Protection against sunburn light: As the sunshine is really strong, you'd better take the sunglasses, sunhat and suntan lotion etc. Ladies should take the high SPF sun-cream.
Medicine: Take an adequate supply of any prescription medication you use regularly, including inhalers for asthma. Most over-the-counter medicines, such as aspirin and anti-diarrheal pills, are available in Lhasa, but are more difficult to obtain outside of urban areas. If you wear contact lenses, be sure to bring enough cleaning solution for the term, since this is hard to find, and expensive. Bring diamox pills which is believed to prevent the altitude sickness. Please consult your doctor prior to your travel to Tibet.
Trekking equipments: Some trekking supplies (down and fleece jackets, boots, bags, etc.) are available in Lhasa, but it is better to be prepared before departing since supplies are unpredictable.
Water: Water purification equipment, such as hand pump filters, is not necessary, as bottled mineral water and thermoses of boiled water are available everywhere throughout Tibet. Water purification tablets can be useful during trekking.
Electrical current: The electrical current in Tibet is 220v, AC 50 Hz. There are numerous different plug types used in Tibet , so it might be easier to purchase an adapter once you get there.