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 scarcity in Africa according to the World Health Organization, contributes to the spread of waterborne diseases including typhoid fever, cholera, dysentery and diarrhea, and to the spread of diseases such as malaria whose vectors rely on such water resources, and can lead to diseases such as trachoma, plague, and typhus. Additionally, water scarcity causes many people to store water within the household, which increases the risk of household water contamination and incidents of malaria and dengue fever spread by mosquitoes. These waterborne diseases are not usually found in developed countries because of sophisticated water treatment systems that filter and chlorinate water, but for