With the help of thermal balance integrated method and fisher price on the basis of introduction of temperature indignation front the analytical decision of a problem of non-stationary heat conductivity is obtained under boundary conditions of the third kind with variable in time factor of heat return.Graphs of isotherms distribution and velocity of their movement are constructed.In Bull Bars order to provide for the accuracy of the solution the additional boundary conditions defined from initial differential equation and basic boundary conditions, including the data obtained at the front of temperature indignation are entered.