The interactive eLearning course with audio has been discontinued as from October 2016 but continues to be available through the slide presentation including comments. This presentation provides an introduction to infra-red thermography and the associated background science . It explains, by way of 65 slides, many of the basic terms associated with the activity. Four main areas of industrial application are discussed, and practical examples from each of these areas are presented. We apologize for the inconvenience.