A power electronic device, comprising: a housing; a conductive element positioned within the housing and rated for at least a medium voltage; a cooling system in fluid communication with the conductive element, the cooling system comprising a plurality of outlet conduit elements that are positioned within the housing; a plurality of temperature sensing tags (311a-311c) wherein each of the tags is attached to one of the outlet conduits and comprises a power supply, a temperature sensor, and an antenna; and a data collection unit comprising a receiver that is configured to receive signals from the antennae of the temperature sensing tags; wherein the power supplies comprise at least one of: a thermoelectric device, an induction coil positioned to harvest magnetic energy from a field near the conductive element when the conductive element is operational and convert the magnetic energy to a voltage, and an antenna positioned to harvest electromagnetic energy from a field near the conductive element when the conductive element is operational and convert the electromagnetic energy to a voltage; and wherein at least one of the temperature sensing tags comprises an energy storage device configured to store a charge, wherein the at least one of the temperature sensing tags transmits an identifier and data representative of sensed temperature when the stored charge reaches a threshold. a housing; a conductive element positioned within the housing and rated for at least a medium voltage; a cooling system in fluid communication with the conductive element, the cooling system comprising a plurality of outlet conduit elements that are positioned within the housing; a plurality of temperature sensing tags (311a-311c) wherein each of the tags is attached to one of the outlet conduits and comprises a power supply, a temperature sensor, and an antenna; and a data collection unit comprising a receiver that is configured to receive signals from the antennae of the temperature sensing tags; wherein the power supplies comprise at least one of: a thermoelectric device, an induction coil positioned to harvest magnetic energy from a field near the conductive element when the conductive element is operational and convert the magnetic energy to a voltage, and an antenna positioned to harvest electromagnetic energy from a field near the conductive element when the conductive element is operational and convert the electromagnetic energy to a voltage; and wherein at least one of the temperature sensing tags comprises an energy storage device configured to store a charge, wherein the at least one of the temperature sensing tags transmits an identifier and data representative of sensed temperature when the stored charge reaches a threshold. a thermoelectric device, an induction coil positioned to harvest magnetic energy from a field near the conductive element when the conductive element is operational and convert the magnetic energy to a voltage, and an antenna positioned to harvest electromagnetic energy from a field near the conductive element when the conductive element is operational and convert the electromagnetic energy to a voltage; and wherein at least one of the temperature sensing tags comprises an energy storage device configured to store a charge, wherein the at least one of the temperature sensing tags transmits an identifier and data representative of sensed temperature when the stored charge reaches a threshold.