ASHRAE Standard 55-1981 and Chapter 8 of ASHRAE Handbook—1981 Fundamentals specify the environmental conditions that are thermally acceptable to most people at different levels of clothing insulation and metabolic activity. It is necessary for users of these documents to determine what types of clothing provide different amounts of insulation.

Results indicated that garment insulation values can be predicted with accuracy from fabric thickness and the amount of body surface area covered by the garment. Together, ensemble weight (without shoes) and the amount of body surface area covered by different numbers of fabric layers are fairly good predictors of ensemble insulation.