We apply the theory established in ref.  and the general results to treat heat fluctuations in dielectric materials, by considering the phonon heat conduction in one, two and three dimensions, as well as in metals, where we deal with electronic heat conduction. We compare our results with an exact solutions from an exact model for the nonequibrium fluctuations in a linear harmonic chain based on an information-theoretical approach. These solutions coincide reasonably. And so prove the theory presented in  is correct.