A drawback of the Personal Protective Equipment (PPE) providing firefighters protection under extreme conditions is their insufficient dissipation of heat and sweat. As a result the body core temperature increases to dangerous levels. At the German Institutes for Textile and Fiber Research Denkendorf (DITF), intensive research is being conducted on cooling materials to protect firefighters from heat related deaths. For this purpose, an active water cooling textile, consisting of different layer constructions and absorption materials has been developed. The cooling mechanism is based on evaporation of the stored water in the absorption material. Two different constructions (an open and a closed system) with various nonwoven water absorption structures, which have been integrated into a textile layer structure, have been developed. We used superabsorbents polymer fleeces and natural viscos fleeces with different weights. In preparation the exact grammage and the absorptive capacity were measured. In addition we visualized the stream in the air-conveying layer. As main test method a special thermos-physiological measurement system has been used to measure the cooling ability of the different layer constructions. Moreover possible cooling effects can be calculated.