The assembly (1) has a drum body rotatably supported around a drum axle and provided for accommodating a hose (8). The drum axle is designed as a fluid pipe at which the hose is connected. The drum axle is provided with a multiport swivel (11) that connects the drum axle with a non-rotatable supply pipe. An electrical heating unit (16) is arranged in the hose, and a slip-ring arrangement is arranged between the swivel and the drum body for supplying electrical energy to the heating unit. A temperature measuring device (T2) measures temperature of fluid flowing through the hose. An independent claim is also included for a method for operating a hose drum assembly.