In a method and device for correction of a B0 field drift in a temperature map acquisition by magnetic resonance tomography, a fluctuation measurement is calculated per pixel from a number of magnetic resonance tomography phase images of an examination subject or from temperature maps derived therefrom. Using this fluctuation measurement, pixels of the phase images or temperature maps with low fluctuation are determined, and corresponding pixels of a phase image to be corrected or of a temperature map to be corrected are selected using the pixels determined as having low fluctuation. The phase image to be corrected or the temperature map to be corrected is adjusted to a reference phase image or a reference temperature map such that the selected pixels of the phase image to be corrected or of the temperature map to be corrected are calibrated to corresponding pixels of the reference phase image or of the reference temperature map.