a method of using the system 10 the mannequin 20 is placed into a room or enclosure wherein the air temperature air movement and humidity are maintained at a substantially constant level it is to be understood by one of skill in the art that the room or enclosure utilized in the present invention does not need to comprise a climate control chamber such as is known in the art permitting a substantially reduced cost of operation for the present invention the heating system is activated when the mannequin 20 is unclothed and the average surface temperature of the mannequin 20 is adjusted to simulate that of human or other homeothermic mammal skin and is maintained at this level automatically throughout the measurement period while collecting watt meter 41 data the garment 90 to be tested is then put on the mannequin 20 and the watt readings recorded with the watt meter 41 the differences between the unclothed and clothed conditions provide quantitative information on the garment 39 s insulation properties the breathability of the garment 39 s fabric can also be determined separately by first closing the ventilation openings of the garment such as at the arms the legs and the neck tests may be conducted under a plurality of conditions.