Infrared thermography (IRT) is a telemetric, or remote measuring, technique that maps emitted radiation into a twodimensional image representative of the distribution of the temperature on the emitting surface.'In the 1960s the first IRT applications were carried out by the aerospace, welding, automotive, and electric industries. Then, in the 1970s and 1980s, the technique was applied to medical, agricultural, and building-maintenance uses. In the same period thermal math models of heat transfer inside structures and materials were developed to improve the comparative evaluation between sound areas and anomalies and to improve the temperature distribution in those regions. In recent decades considerable IRT research has been conducted in Italy, both in the laboratory and in the field at buildings important to Italy's cultural heritage. Thermal anomalies have been shown to be related to the local thermal properties of the materials and to defects in the elements examined. 2 Controls became reliable thanks to new algorithms applied in signal processing in the thermocameras. Today IRT is often used in different phases of building restoration: during preliminary investigations, during the restoration process itself, as a tool for final inspection, and later as part of a cyclical maintenance plan. IRT investigation permits researchers to gather information about the location, shape, material characteristics, and state of decay of building elements and systems. Surface-temperature distribution evaluated with respect to particular boundary conditions permits the detection of discontinuities and alterations to building structures.