The tea houses also provide hot meals for trekkers. Since many establishments are located well above the tree line - accessible only by a very rocky, dirt road (and some only by foot) - both wood and gas are very expensive. The solution during the day is to use six foot diameter solar reflectors for cooking large pots of food at once. Also, to aid in conservation, all the trekkers are asked to place their orders in advance and are encouraged to order the same or similar dishes to make the cooking more efficient. All meals are then cooked and served at one time.