This symposium will broadly cover current and emerging thermal materials, with aspects ranging from nanoscale and non-equilibrium heat transport, thermal Hall effect, devices, applications, to new theories. The first part of the symposium will focus on emerging materials with extremely high or extremely low thermal conductivity for thermal management, materials systems for thermoelectric, thermophotovoltaics, thermo-electrochemical, thermo-acoustic, -ferroelectric, and -magnetic energy harvesting, storage, as well as advanced control and functionalities. Discussions will include the rational design, chemical synthesis, growth mechanisms, fabrication routes, property optimization and external field control, and new fundamental science. The Second part of the symposium will focus on recent developments of nanoscale heat transport with both new experimental metrologies and theoretical methods from density functional theory (DFT) to machine learning. In particular, with continuing miniaturization of devices, as well as continuing development of experimental techniques, unprecedented length and time scales can now be probed, thus enabling new insights of non-Fourier heat conduction, convection, near-field radiation, and their interactions with materials, all now being intensively investigated. Discussions will include recent measurements over nanoscales and interfaces using advanced characterization techniques such as pump-probe thermoreflectance measurements, Raman thermometry, atomic force microscopy based thermometry, and recent modeling using atomistic tools such as ab initio DFT, molecular dynamics, and Wigner and Green's function formalisms, etc., as well as multi-scale modeling such as phonon Boltzmann Equation and Monte Carlo simulations. Possible topics of interest are thermal transport in extreme environments (high pressure/temperature), non-Fourier thermal transport and conductance via other than phonon and electrons heat carriers, thermal radiation from metamaterials, nano-thermodynamics. The Third part of the symposium will focus on devices and applications at across multiple time and length scales: examples include but are not limited to nanoscale thermal rectification devices, mesoscopic scale phononic crystals, and macroscopic thermal batteries, solar thermal plants, data farms, and the Internet of things.