A system for monitoring a device, the system comprising: an infrared camera; a processing unit; and an output unit; wherein, the infrared camera is configured to acquire a plurality of infrared images of the device, wherein the plurality of infrared images comprises a first infrared image and a second infrared image acquired a time period after the first infrared image; wherein the processing unit is configured to determine a pixel in the first infrared image with a hottest temperature and determine a pixel in the second infrared image with a hottest temperature; wherein the processing unit is configured to determine a first number of pixels in the first infrared image that have a temperature within a threshold temperature of the hottest temperature of the first infrared image and determine a second number of pixels in the second infrared image that have a temperature within the threshold temperature of the hottest temperature of the second infrared image; wherein the processing unit is configured to determine a temperature magnitude comprising utilization of the hottest temperature in the second infrared image and/or a hottest temperature in a different infrared image of the plurality of infrared images acquired at a different time to the second infrared image; wherein the processing unit is configured to determine a rate of change of temperature comprising utilization of the hottest temperature in the second infrared image and the hottest temperature in the different infrared image and a time duration between the acquisition of the second infrared image and the acquisition of the different infrared image; wherein the processing unit is configured to determine that a hot spot exists in the device and/or a hot spot is developing in the device comprising utilization of a comparison between the first number of pixels and the second number of pixels and the temperature magnitude and the rate of change of temperature; and wherein the output unit is configured to output an indication of a fault in the device on the basis of the determination that a hot spot exists and/or is developing. wherein, the infrared camera is configured to acquire a plurality of infrared images of the device, wherein the plurality of infrared images comprises a first infrared image and a second infrared image acquired a time period after the first infrared image; wherein the processing unit is configured to determine a pixel in the first infrared image with a hottest temperature and determine a pixel in the second infrared image with a hottest temperature; wherein the processing unit is configured to determine a first number of pixels in the first infrared image that have a temperature within a threshold temperature of the hottest temperature of the first infrared image and determine a second number of pixels in the second infrared image that have a temperature within the threshold temperature of the hottest temperature of the second infrared image; wherein the processing unit is configured to determine a temperature magnitude comprising utilization of the hottest temperature in the second infrared image and/or a hottest temperature in a different infrared image of the plurality of infrared images acquired at a different time to the second infrared image; wherein the processing unit is configured to determine a rate of change of temperature comprising utilization of the hottest temperature in the second infrared image and the hottest temperature in the different infrared image and a time duration between the acquisition of the second infrared image and the acquisition of the different infrared image; wherein the processing unit is configured to determine that a hot spot exists in the device and/or a hot spot is developing in the device comprising utilization of a comparison between the first number of pixels and the second number of pixels and the temperature magnitude and the rate of change of temperature; and wherein the output unit is configured to output an indication of a fault in the device on the basis of the determination that a hot spot exists and/or is developing.