Development of experimental methods to measure temperature fields and velocity fields in fluid flows using Magnetic Resonance Imaging Zusammenfassung: The work described in this thesis aims to establish high spatially resolved 2D and 3D MR thermometry (MRT) in complex fluid flows. It studies in detail the accurate and precise measurement of temperature with MRT as well as MR velocimetry (MRV) in thermofluid applications (involving fluid mechanics and thermodynamics) simultaneously within a single measurement session. Experimental results using the newly developed methods and techniques demonstrate that MRI offers great potential to gain new insights into fundamental heat transfer phenomena and that it can be of great interest as an additional non invasive measurement modality