Thermography and thermal symmetry

The terms infrared thermography and infrared thermal imaging are common terms used when visualising and quantifying skin surface temperature using infrared cameras. In healthy subjects, the pattern of skin surface temperature in the same body area on contralateral sides of the body is regarded by many as being very similar. Arising from this the terms thermal symmetry (reflecting normal physiology) and thermal asymmetry (reflecting abnormal physiology) have arisen, the latter being often used in helping medical practitioners to make a diagnosis. However, these terms mean different things to different people and there is some confusion about their use. In this short communication we explain why this has come about.