Abstract: A heated fluid surgical instrument including a palm-sized handpiece having a cannula adapted to be inserted into a patient's body by way of a natural access (e.g., mouth) or a small incision. A channel is provided within the handpiece and the cannula for permitting the passage of a surgical accessory implement to the surgical site. Additional, channels are provided for passing fluid pumped into the handpiece from a remote fluid source to the surgical site. An irrigation control valve assembly on the handpiece permits a surgeon to selectively direct the flow of fluid through the handpiece and into one of two fluid flow paths. One of the paths heats the fluid and passes it to the surgical site to effect a therapeutic result. The other path sends the fluid directly to the surgical site.