A sensor guide wire for an intravascular measurement of a physiological variable in a living body, may comprise a proximal tube portion; a distal end portion; and a sensor element configured to measure the physiological variable based on exposure to fluid in the living body. The sensor guide wire may further comprise a mounting structure supporting the sensor element in a freely suspended manner in a lumen within the sensor guide wire and/or a cylindrical-shaped jacket forming an interior space housing the sensor element and extending from a distal end of the proximal tube portion to a proximal end of the distal end portion in which the outer circumferential wall of the jacket includes a plurality of slots located between at least one aperture of the outer circumferential wall and one of the distal and proximal ends of the jacket.