A process is provided for mapping temperatures in an enclosure. A spectral band for a multi-spectral image-capturing device is selected. An intensity-temperature mapping is generated by performing an intensity-temperature calibration based on an intensity of an image pixel in a field of view (FOV) generated by the multi-spectral image-capturing device, a corresponding temperature measurement, and a selected device setting of the image-capturing device. An emitted radiation is detected based on a first spectral image in the FOV. At least one region is determined whether it is poor responsive, which is underexposed or overexposed, such that an accurate temperature is unable to be estimated based on a temperature value associated with the spectral band. Temperatures of the at least one poor responsive regions are replaced with temperatures from corresponding acceptable regions from at least one other spectral image to provide an extended temperature mapping of the enclosure.