The functions of graphene have garnered significant attention in recent research. A profound understanding of the principles of temperature-dependent electromagnetic responses is crucial for guiding the design of advanced functional materials and devices. From this perspective, the thermally tailored mechanisms of polarization genes and conduction genes are emphasized. The synergistic effect between thermally tailored polarization relaxation and charge transport behaviors is revealed. More importantly, microwave absorption, electromagnetic shielding, and temperature sensing at elevated temperatures are discussed by customizing the conduction and polarization genes. The tunable variable-temperature electromagnetic performance enables the possibilities of diversified electromagnetic energy conversion. Three electromagnetic energy conversion devices for consuming waste electromagnetic energy are predicted, which can support the next generation of energy management and smart devices and promote efficient utilization of resources and sustainable development.