The theory of **relativistic heat conduction (RHC)** claims to be the only model for heat conduction (and similar diffusion processes) that is compatible with the theory of special relativity, the second law of thermodynamics, electrodynamics, and quantum mechanics, simultaneously. The main features of RHC are:

- It admits a finite speed of propagation, and allows for relativistic effects when heat flux transients approach that speed.
- It removes the possibility of paradoxical situations that may violate the second law of thermodynamics.
- It, implicitly, admits the wave–particle duality of the heat-carrying “phonon”.

These outcomes are achieved by (1) upgrading the Fourier equation of heat conduction to the form of a Telegraph equation of electrodynamics, and (2) introducing a new definition of the heat flux vector. Consequently, RHC gives rise to a number of interesting phenomena, such as thermal resonance and thermal shock waves, which are possible during high-frequency pulsed laser heating of thermal insulators. The main appealing feature of the theory is its mathematical *elegance and simplicity*.

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