This International Standard provides the general principles of a test method for evaluating the performance of complete garments or protective clothing ensembles in a flash fire or other short duration exposures. This test method characterizes the thermal protection provided by garments, based on the measurement of heat transfer to a full-size manikin exposed to a laboratory simulation of a fire with controlled heat flux density, duration and flame distribution. The heat transfer measurements can also be used to calculate the predicted skin burn injury resulting from the exposure. In addition, observations are recorded on the overall behaviour of the test specimen during and after the exposure. This method is useful for three types of evaluation: a) comparison of garment or ensemble materials; b) comparison of garment or ensemble design; and c) evaluation of any garment or ensemble prototype for a particular application or to a specification. Each type of evaluation has different garment or ensemble requirements because the test results are dependent on the test material performance, on the garment size, on the garment design and on the use of ensemble components. The results obtained apply only to the particular garments or ensembles, as tested, and for the specified conditions of each test, particularly with respect to the heat flux density, duration and flame distribution. For the purposes of this test method, the incident heat flux density is limited to a nominal level of 84 kW/m2. This International Standard is intended to be used to measure and describe the behaviour of complete garments or protective clothing ensembles in response to convective and radiant energy under controlled laboratory conditions, with the results used to optimize garment combinations and designs. This International Standard is not intended to be used to compare the properties of garment materials or combinations of materials unless the test specimens are absolutely identical in size and design. Furthermore, this International Standard is not intended to be used to describe or appraise the fire hazard or fire risk under actual fire conditions. However, the results of this test can be used as elements of a fire risk assessment which takes into account all of the factors that are pertinent to an assessment of the fire hazard of a particular end use. Considerations for the use of this test method are provided in Annex A. Inter-laboratory data for the test method are provided in Annex B.