This International Standard defines a standardised method to evaluate the general thermal comfort of people in a space and the degree of discomfort (thermal dissatisfaction) of people exposed to moderate thermal environments. It defines the analytical determination and interpretation of thermal confort using calculation of PMV (predicted mean vote) and PPD (predicted percentage of dissatisfied) and local thermal comfort criteria, giving the environmental conditions considered acceptable for general thermal comfort as well as those representing local discomfort. It is applicable to healthy men and women exposed to indoor environments where thermal comfort is desirable, but where moderate deviations from thermal comfort occur, in the design of new environments or the assessment of existing ones. Although developed specifically for the work environment, it is applicable to other kinds of environment as well. It is intended to be used with reference to ISO 28803, when considering persons with special requirements, such as those with physical disabilities. Ethnic, national or geographical differences need also to be taken into account especially when considering non-conditioned spaces. Guidance is given in clause 8 and 10 in the guideline ISO DTR XXXXX