A sensor arrangement (1) for measuring a pressure and a temperature in a fluid is disclosed. The sensor arrangement (1) comprises a temperature sensitive electrical element (3) and a pressure sensing electrical element (6), the temperature sensitive electrical element (3) and pressure sensing electrical element (6) are both coupled to one side of a metallic membrane structure (4,16). The metallic membrane structure is arranged to pass on the temperature of the fluid which is at the other side of the membrane structure (4,16) to the temperature sensitive electrical element (3) and to pass on the pressure in the fluid to the pressure sensing electrical element (6). In this way a combined pressure and temperature sensor is obtained which is applicable in vehicle air-conditioning systems working with CO.sub.2 as refrigerant.