Abstract: A method and apparatus for effecting necrosis of a tissue lining of a mammalian body cavity, particularly a uterine endometrium, by introducing an applicator comprising a distendable bladder connected to a catheter into the uterus, distending the bladder by introducing a non-toxic fluid under pressure, heating the fluid by means located internal to the bladder to a temperature of 190.degree. to 215.degree. F. and preferably 210.degree. F. for a period of 4 to 12 minutes and preferably 6 minutes and regulating said apparatus by means located external to the uterus, thereby cauterizing substantially the entirety of the tissue lining, particularly the endometrium. An agitator circulates the fluid within the distendable bladder to help keep the fluid at a uniform temperature.