Pump arrangement (20) for conveying a fluid, with a housing (22), with a first rotatably mounted pump member (24), and with a second rotatably mounted pump member (26), wherein a fluid-conveying effect is produced by means of a relative rotary movement between the first and the second pump member (24, 26), wherein the first pump member (24) can be driven by an electric motor (42) which is arranged concentrically to the first pump member (24) and which has a stator (44) and a rotor (46), wherein the rotor (46) is fixed to the first pump member (24) and wherein the pump arrangement (20) is constructed in such a way that fluid is present in an annular gap (58) between the rotor (46) and the stator (44). In this case, the pump arrangement has temperature control means for heating the fluid in the annular gap (58).