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
Little cherry disease establishment of the disease, guidelines typically call for testing of rootstocks and budwood before planting, removal of all trees known and suspected to be infected and eradication of ornamental and wild cherry trees from the surrounding area. Short-distance spread of the disease occurs through transmission of the viruses by insect vectors. Little cherry virus-2 is spread by scale insects of the family Pseudococcidae, primarily the apple mealybug ("Phenacoccus aceris"). In areas where the apple mealybug is commonplace, application of insecticides prior to cutting infected trees are routinely used to stop the spread of little cherry disease within orchards. Little cherry