Over 90% of all electrical energy used in transportation and in heating and cooling originates from thermal processes. Even small efficiency improvements in the control and conversion of thermal energy would significantly reduce overall energy consumption. There is increasing demand for sustainable cooling technologies, and removing heat efficiently is critical to the performance and reliability of smaller and denser integrated circuits. The goal of the workshop is to identify and describe challenges in thermal transport and energy conversion, and to provide information for all stakeholders about the state-of-the-art in science and promising research directions for the near- to mid-term future.