ARC Thermal performance tests (ASTM F1959-99) have shown a single layer of Flamestop NOMEX IIIA 7.6oz/sq.yd. fleece provides the same protection as 2 layers of fire resistant clothing totaling between 10-14oz./sq. yd.* Thermal mannequin testing (see RealVideo footage) (ASTM F1930-00) predicts one of the lowest percentage body burn injuries ever recorded for single layer fabric. (6.8% at 1.9 cal cm2 for 4 seconds)*