The application of infrared thermography in sports has increased over the past decades due to its main technical advantages: it is a non-invasive, non-radiating, and low-cost tool. Infrared thermography is used in various areas of sport, including injury detection in sports medicine, the assessment of human thermoregulation, applications in animal sports, and the analysis of heat transfer in sports garments and equipment. Although infrared thermography is considered a fast and easy-to-use technique, a rigorous protocol is essential to ensure accurate and repeatable measurements. Moreover, being familiar with the latest sports-related studies using this technique is crucial for understanding its potential and limitations. The second edition updates all chapters-an essential step given the significant advances in the field since the first edition was published in 2017-and introduces new chapters on topics not previously covered. This book serves as an essential guide for newcomers to infrared thermography in sports science, as well as a valuable reference for experienced users, and aims to bridge the gap between laboratory knowledge and its application in the sports field.