  In this paper the theory is developed for creating a material in which the
heat is transmitted along a given line. This gives a possibility to transfer
information using heat signals. This seems to be a novel idea. The technical
part of the theory is the construction of the potential $q(x)$. This potential
describes the heat equation $u_t = \Delta u - q(x)u$ in the limiting medium
which is obtained after the small impedance particles are distributed in a
given domain. A numerical method is also established to construct numerically
such a potential.
