A magnetic resonance examination system (10) includes a superconducting main magnet (20) surrounding an examination region (18) and generating a main magnetic field in the examination region (18) A magnetic field gradient system (30) selectively causes alternating gradient magnetic fields in the examination region (18). The magnetic field gradient system (30) is disposed outside of the main magnet (20). In order to provide stable operation of the superconducting main magnet (20) of a magnetic resonance examination system (10) with such a magnetic field gradient system (30), the magnetic resonance examination system (10) is provided with a predicting device (91) and a preventing device (92) The predicting device (91) predicts the behavior of the main magnet (20) due to the gradient magnetic fields (e.g., by calculating the expected heat load of the main magnet caused by an imaging protocol) and the preventing device (92) prevents, based on the predicted behavior of the main magnet (20), the main magnet (20) from quenching.