It's often difficult to get adequate nutrition while traveling so it is strongly suggested that you bring multivitamins and food that requires little or no preparation such as dried fruit or soup mix that can be added to hot water. Travelers should try to maintain a water quota of 4 liters a day, even if they feel they such an amount is excessive. Drinking water should always be boiled, filtered, or purified with iodine tablets. Water boils faster due to the higher altitude, so water should be boiled for at least 10 minutes. Bottled water is available in more commercial areas, but the seal should be unbroken. Gatorade or an electrolyte mix such as Electrolade help maintain healthy fluid levels. Any food you buy should be cooked at a high temperature. Try sticking to fruit that can be peeled in order to ensure that it is sanitary. All other fruits and vegetables should be washed in boiled or purified water. Cold items such as ice cream, ice cubes or salad should especially be avoided.
Due to lower sanitation standards, diarrhea is not uncommon to travelers. Visitors experiencing diarrhea should be sure to drink lots of fluids since so much fluid is leaving the body. Rehydration packets or electrolyte mixes containing potassium and sodium are extremely helpful. You should avoid dairy products, alcohol, spicy food, and food high in fat.
The temperature can fluctuate highly throughout the day. Because the temperature can drop to extreme low, you should bring plenty of warm clothing made of wool, polypropylene, and silk. A warm hat can prevent a lot of heat loss. Frostbite can affect the extremities, and symptoms include numbness, itching, pain, and a waxy or white-ish look to the skin.
Generally, the temperature is cool, and the air is very dry. Moisturizer, sunscreen and quality sunglasses are a necessity. Dust presents a major problem because it becomes trapped in the eyes and mouth, but a banana or scarf can help the situation. Contact lens wearers need to bring a pair of glasses because dust and smoke can be irritating to a degree that it is impractical to wear contacts.