ASTM F2732 : 23

1.1 This standard practice covers the determination of the temperature rating of a cold weather protective clothing garment or system of garments when worn with one of two base ensembles. It involves measuring the thermal resistance (insulation) value of a clothing ensemble (base ensemble plus the garment or garment system being evaluated) with a heated manikin in accordance with Test Method F1291. The result is used in a heat loss model to predict the lowest environmental temperature for comfort.

1.2 The predictive model used in this standard estimates the evaporative heat loss from a person wearing cold weather clothing as opposed to measuring the evaporative resistance on a sweating manikin. If a person is active and gets overheated in a cold environment, he/she is usually able to adjust the garments to dissipate excess heat.

1.3 The temperature ratings estimated by this standard practice are guidelines for thermal comfort, determined from a whole-body heat loss model (see Annex A1). Therefore, localized cooling, discomfort, and even frostbite could still occur at extremely low temperatures because clothing insulation is not evenly distributed over the body surface. In addition, some body parts (for example, ears, fingers, toes) have a high surface area relative to their mass, and consequently lose heat at a faster rate than other parts of the body.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International StandardDetails, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.