WHEN ONE SPEAKS of clinical radiology, roentgenography is usually assumed to be the basis of the subject; but, in this report, thermoradiography or thermography is concerned with infrared radiations spontaneously emanating from the human body.
Infrared energy, in the form of invisible "light" is emitted by every object whose temperature is above absolute zero; this self-emitted energy may be collected optically, transformed into proportional electrical impulses, and then converted to visible light to form a picture or thermogram.1 Since the amount of infrared given off by any object is a function of its temperature, such thermograms are in reality quantitative representations of the object's surface temperature. Thermography thus constitutes a powerful tool for nondestructive testing which has been applied successfully, not only in situations in industry, but also in the field of medicine.
In a sense, the human body is at all times "incandescent" or self-luminous within the infrared portion of the electromagnetic spectrum. The human
R. Bowling Barnes, J. Gershon-Cohen. Clinical Thermography. JAMA. 1963;185(12):949–952. doi:10.1001/jama.1963.03060120059022