  This paper is devoted to study the thermal aspects of a photon gas within the
context of Planck scale modified dispersion relations. We study the spectrum of
radiation and the correction to the Stefan Boltzmann law in different cases
when the Lorentz symmetry is no longer preserved. Particularly, we examine two
models within the context of CPT even and CPT odd sectors respectively. To do
so, three distinct scenarios of the Universe are considered: the Cosmic
Microwave Background (CMB), the electroweak epoch, and the inflationary era.
Afterwards, we also provide for both theories the analyses of the Helmholtz
free energy, the mean energy, the entropy and the heat capacity.
