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
Bronze disease Bronze disease Bronze disease is the irreversible and nearly inexorable corrosion process occurring when chlorides come into contact with bronze or other copper-bearing alloys. It occurs as a dark green or a lighter fuzzy green coating on copper, bronze, and other copper-bearing alloys generally due either to contamination by salt water or after burial in dirt (as chloride salts are generally present in soil to some degree). If not treated, complete destruction of the affected artifact is possible. Transfer of chlorides from the contaminated artifact to other artifacts can spread the condition. Bronze disease is the chloride corrosion of cupreous