The present invention refers to a device (112) for monitoring an emission temperature of at least one radiation emitting element (114), a heating system (110) for heating at the least one radiation emitting element (114) to emit thermal radiation at an emission temperature, a method for monitoring an emission temperature of at least one radiation emitting element (114) and method for heating the at least one radiation emitting element (114) to emit thermal radiation at an emission temperature. Herein, the device (112) for monitoring an emission temperature of at least one radiation emitting element (114) comprises - at least one radiation sensitive element (126), wherein the at least one radiation sensitive element (126) has at least one sensor region (128), wherein the at least one sensor region (128) comprises at least one photosensitive material selected from at least one photoconductive material, wherein the at least one sensor region (128) is designated for generating at least one sensor signal depending on an intensity of the thermal radiation emitted by the at least one radiation emitting element (114) and received by the sensor region (128) within at least two individual wavelength ranges, wherein the at least one radiation sensitive element (126) is arranged in a manner that the thermal radiation travels through at least one transition material (116) prior to be received by the at least one radiation sensitive element (126), wherein the at least one transition material (116) is at least partially transparent for the thermal radiation within the two individual wavelength ranges; and at least one evaluation unit (138), wherein the at least one evaluation unit (138) is configured to determine the emission temperature of the at least one radiation emitting element (114) by comparing values for the intensity of the thermal radiation within the at least two individual wavelength ranges.