In a magnetic resonance system and operating method, antenna elements in an antenna array are disposed around an examination volume, and each antenna element has a separate transmission channel and reception channel associated therewith. The magnetic resonance apparatus is operated to obtain magnetic resonance signals, from which amplitude and phase information are derived for the individual antenna elements, and this information is used to subsequently operate the antenna elements in the array to emit RF energy with a predetermined phase and amplitude so as to generate focused RF energy for hyperthermic treatment. The magnetic resonance apparatus can also be used to obtain magnetic resonance signals in intervals which during which the hyperthermic treatment is interrupted, from which the temperature of the region being treated can be ascertained.