Water heating by a domestic water heater. Two conflicting safety issues affect water heater temperature—the risk of scalding from excessively hot water greater than , and the risk of incubating bacteria colonies, particularly "Legionella", in water that is not hot enough to kill them. Both risks are potentially life-threatening and are balanced by setting the water heater's thermostat to . The European Guidelines for Control and Prevention of Travel Associated Legionnaires’ Disease recommend that hot water should be stored at and distributed so that a temperature of at least and preferably is achieved within one minute at points of use. If there
Water-dropper (calligraphy) Water-dropper (calligraphy) A is a small device used in East Asian calligraphy as a container designed to hold a small amount of water. In order to make ink a few drops of water are dropped onto the surface of an inkstone. By grinding an inkstick into this water on the inkstone, particles come off and mix with the water, forming ink. Water-droppers may be made of copper, jade or other stone, or ceramic. A water-dropper has two small holes for water and air, and is designed so that only a few drops of water can fall at one time. There