Abstract: A method and apparatus for thermal imaging is disclosed which enables a clinician to obtain visual images reflecting metabolic activity within a patient's body. A scanning system is configured to scan an area on the patient's body to obtain infrared intensity data. The data is digitized and processed prior to being displayed. The data processing includes a "slicing" function in which infrared intensity values are assigned color values in accordance with an output window. By redefining the mapping of the output window to the color spectrum, the data can be manipulated such that the visual display reflects metabolic activity within the patient's body under the scanning area.