In the case reported here, the female companion of a 73-year-old man dismembered his body after killing him. The dismemberment included the prolonged boiling of the decapitated head in a water-filled metal pot, with wine added to offset the odor. This treatment resulted in marked shrinkage of cranial dura mater, separation of dura mater from the skull, and extrusion of brain fragments into the resultant enlarged epidural space through a dural defect due to the disproportionately greater shrinkage of dura mater compared to brain parenchyma. This resulted in curd-like brain fragments filling an enlarged epidural space and overlying a shrunken, leathery dura mater. The cranial dura mater, still adhering to the skull base, resembled a "shrunken brain" in contour but contained only the remnants of brain tissue not already extruded through the dural defect. Based on the autopsy and experimental observation, the rare occurrence of the thermal artifact observed in this case requires a distinctive combination of factors. First, there must be thermal injury to the head area. In this case the temperature was in the range of only approximately 200 degrees Fahrenheit. Second, some time is required, at least a few minutes, subject to variation in rate of temperature increase, maximum temperature elevation, relative exposure of the head to the heat source, and other undetermined factors. Third, the dura mater must separate from the inner table of the skull, creating an enlarged epidural space into which the brain tissue can extrude. Fourth, disproportionate shrinkage of dura mater more than brain parenchyma is required in order to create the pressure differential that favors extrusion of a significant volume of brain tissue into the extradural compartment. Fifth, there must be a defect in the shrunken dura through which brain parenchyma can extrude into the enlarged epidural space created by the separation and shrinkage of the dura mater from the inner table of the skull. Sixth, persistence of a fluid environment in the cranial cavity is probably necessary for this type of thermal artifact to occur. 4 figures and 17 references