Thermal Imaging Provides a Window Into the Metabolism of C. elegans

All organisms carry out metabolic processes, and energetic waste is lost as heat. We have developed a thermal imaging technique to investigate waste heat production in the nematode worm C. elegans. In the two studies presented, thermal IR imaging was used to examine the difference in heat output by simultaneously imaging living and dead C. elegans. A cold object was used in reflectance mode to suppress the thermal background to reveal a clear, replicated, difference in the thermal output and cooling rate of living and dead C. elegans. FT-IR spectroscopy demonstrates that the measured temperature difference is the result of a difference in kinetic temperature, not in the thermal emissivity of the living and dead worms. This novel investigative tool opens the door to the study of previously inaccessible thermal biology of small invertebrate animals.