at the request of the naval sea systems command, the navy clothing && textile research facility (nctrf) conducted a seven-phase investigation of kynol/nomex fabrics for possible use in fire-retardent (fr) shipboard utility uniforms in place of fire-retardent-treated (frt) cotton. nctrf first surveyed the u.s protective clothing market and then tested three kynol/nomex blends in its laboratories to determine their physical, abrasion resistance, and laundering properties. meanwhile, nctrf ran physiological tests to show the heat stress imposed by the various uniforms and conducted a full array of heat tests ranging from laboratory tests for heat and flame resistance to full-scale flame-envelopment and close-proximity fire tests. nctrf also administered a shipboard evaluation and subsequently conducted a dyeing and finishing study. finally, nctrf completed a cost evaluation of these uniforms. because these kynol/nomex uniforms showed no significant functional heat-resistant benefits over frt cotton and would cost at least twice as much, nctrf recommended the navy continue using frt cotton for the fr shipboard utility uniforms. keywords: kynol/nomex fabrics; fire-retardent shipboard utility uniforms; fire-retardent materials; military protective clothing; heat stress tests; heat tests; fire resistant textiles.(kt)