  The field theoretical description of thermo-hydrodynamics is given. It is
based on the duality between the physical space--time and the "material
space-time" which we construct here. The material space appearing in a natural
way in the canonical formulation of the hydrodynamics is completed with a
material time playing role of the field potential for temperature. Both
Lagrangian and Hamiltonian formulations, the canonical structure, Poisson
bracket, N\"other theorem and conservation laws are discussed.
