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
Disease in Imperial Rome diseases. The Antonine and Cyprian plagues were transmitted through touch, so a dense population rate would contribute highly to their spread. Deforestation of Rome's cities, particularly near the Tiber River, led to higher disease rates. The causality is as follows: deforestation lead to a rising water table, which increased marshes. This increased the larva in Rome, and in turn increased disease borne from blood-sucking bugs. As in many of today's third world countries, mosquitos and other vectors were carriers of various diseases, such as malaria and the Ross River virus. Influenza, colds, and other ailments were just as apparent, if