The paper is concerned with a method that enables one to determine transient temperature distribution in a heat conducting body from measurements of the surface temperature. It means that an initial condition is not necessary. The solution can be obtained using analytical or numerical methods. It is presented in terms of a series containing the derivatives of the surface temperature with respect to time. In order to calculate the derivatives the regularization method is employed. Some test cases are included. They prove that the proposed method can produce stable results for a wide range of problems except for rapid processes of heat conduction. It means that the method can be employed when, e.g. one estimates the temperature distribution within blooms or ingots during heating or cooling under moderate conditions.
