Infrared Thermography is very intuitive and easy to use. Nevertheless it is very important to understand that, if we want to optimize its use and benefits (mainly in humans), we should take into account the factors that might influence its results and therefore, the correct interpretation of them.

Fernández-Cuevas and collaborators (2015) published a detailed article suggesting a classification of those factors:

• Environmental factors: everything related to the location where the thermal evaluation takes place, as the ambient temperature, humidity or the existence of any source of radiation.
• Individual factors: divided into intrinsic and extrinsic, that is to say, those inherent to the subject (as age, gender or medical history) and these vinculated with the activities done previous to the evaluation (exercise, treatments or food intake).
• Technical factors: not only the resolution or thermal sensitivity of the camera, but also which protocol is performed or how statistics are done.

The application of Infrared Thermography in humans might seem unapproachable after this classification, but the good news is that almost all factors affect symmetrically our body. Therefore, the use of the methodology of thermal asymmetries and a proper protocol to know factors that might create not significant alerts (as medical history) is a strong and reliable way to reduce their impact and optimize the use and benefits of Thermography.

Reference

• Fernández-Cuevas, I., Marins, J. C. B., Lastras, J. A., Carmona, P. M. G., Cano, S. P., García-Concepción, M. Á., & Sillero-Quintana, M. (2015). Classification of factors influencing the use of infrared thermography in humans: A review. Infrared Physics & Technology, 71, 28-55.