The book provides detailed analysis of the thermal comfort assessment of clothing as the basis for developing standards. It discusses general thermal regulation of humans, the thermal protective role of clothing as the way of modelling heat transfer from the body, and the importance of globally accepted test methods and standards to improve quality. New materials necessitate the need for standards improvement and update. The book promotes instruments, methods, implementation of unified specifications, and the definition of standards so that a clear quality management system can be established, for both production systems and testing methods.