Method for monitoring the exposure of one or more subjects to a magnetic field in an environment, comprising the steps of: - providing a spatial map of the components of said magnetic field in said environment; - detecting, over time, a spatial position of said one or more subjects in said environment; and, - for each detected position extracting from said map a corresponding value of the magnetic field associated with said detected position; and - processing said values of magnetic field extracted over time to assess whether they exceed predetermined safety thresholds.