Saunas; Apparatus for disinfecting water; Bath installations; Bath linings, fitted; Baths, bathtubs, whirlpool baths and bath installations; Bathtub enclosures; Bathtub surrounds; Cooling installations for water; Heat pipes to cool heat producing components; Heat pumps; Heaters for hot tubs; Hot tub heaters; Hot tubs; Personal cooling system comprising tubing, a coolant source and temperature controls that may be incorporated into a garment; Refrigerating appliances and installations; Refrigerating machines and installations; Water coolers; Water disinfecting apparatus; Water filtering apparatus; Water filtration and purification units and replacement cartridges and filters therefor