Medical Infrared Thermal Imaging (MITI) is a technique that allows to record skin surface temperature distribution, in a completely safe and innocuous manner. These images provide underlining physiological in-formation on the blood flow, vasoconstriction/vasodilatation, inflammation, transpiration or other processes that can contribute to the skin temperature. This medical imaging modality has been available for nearly six decades and proved to be useful for vascular, neurological and musculoskeletal conditions. Since the recordings are digital, in a form of a matrix of numbers (image), it can be computationally analyzed, by a specialist mostly performing operations of processing and analysis manually supported by proprietary solutions of software. This limits the number of images that can be processed, making difficult the evolution of knowledge, expertise development and information sharing. This chapter aims to disclose the medical imaging method, along with its particularities, principles, applications, advantages and disadvantages. Introducing all available classification and decision making methods that can be employed in digital information along with a literature review of their operation in the biomedical applications of Infrared Thermal Imaging.