The present invention relates to a system (10) for monitoring a three phase switchgear, the system comprising: at least one temperature sensor (20); a processing unit (30); and an output unit (40). One or more of the at least one temperature sensor is configured to acquire first temperature data for each location of at least one location of a first phase (50) of a switchgear (80) at n time points. One or more of the at least one temperature sensor is configured to acquire second temperature data for each location of at least one location of a second phase (60) of the switchgear at the n time points. One or more of the at least one temperature sensor is configured to acquire third temperature data for each location of at least one location of a third phase (70) of the switchgear at the n time points. The at least one temperature sensor is configured to provide the first temperature data, the second temperature data, and the third temperature data to the processing unit. The processing unit is configured to determine n-1 first rates of change of temperature for one or more locations of the at least one location of the first phase with respect to the n first temperature data for the one or more locations of the first phase at the n time points. The processing unit is configured to determine n-1 second rates of change of temperature for one or more locations of the at least one location of the second phase with respect to the n second temperature data for the one or more locations of the second phase at the n time points. The processing unit is configured to determine n-1 third rates of change of temperature for one or more locations of the at least one location of the third phase with respect to the n third temperature data for the one or more locations of the third phase at the n time points. The processing unit is configured to determine a state of the switchgear, wherein the determination of the state of the switchgear comprises utilization of the n-1 first rates of change of temperature for the one or more locations of the first phase and at least n-1 of the n first temperature data for the one or more locations of the first phase and the n-1 second rates of change of temperature for the one or more locations of the second phase and at least n-1 of the n second temperature data for the one or more locations of the second phase and the n-1 third rates of change of temperature for the one or more locations of the third phase and at least n-1 of the n third temperature data for the one or more locations of the third phase. The output unit is configured to output the determined state of the switchgear when the determined state of the switchgear is determined not to be normal or not to be healthy.