A method and apparatus for producing a sterile medical solution is disclosed. The method includes providing at least two components, a first component including bicarbonate ions and a second component including glucose or calcium ions, preheating the first component to a first temperature and the second component to a second temperature, heat sterilizing the first and second components separately to a third and fourth temperatures respectively, the third and fourth temperatures being sterilizing temperatures for the first and second components, maintaining the first and second components approximately at their respective third and fourth temperatures, so as to sterilize the first and second components, cooling the first and second components and delivering the first and second components to a mixing device.