2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197480We study the question of generalizing light-front field theories to finite temperature. We show that the naive generalization has serious problems and we identify the source of the difficulty. We provide a proper generalization of these theories to finite temperature based on a relativistic description of thermal field theories, both in the real and the imaginary time formalisms. Various issues associated with scalar and fermion theories, such as non-analyticity of self-energy, tensor decomposition are discussed in detail.11 pages, 4 figures, Revtex4High Energy Physics - TheoryHigh Energy Physics - Phenomenologytext