[en] An investigation is made of the thermophysical properties of the whole series of heavy lanthanides (Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) in the range from room to melting temperatures. The thermal diffusivity and relative heat capacity are measured with the improved plane temperature wave method and modulation frequencies of heat flow from 3 to 80 Hz. The thermal conductivity of the investigated material is found from the averaged values of the diffusivity and heat capacity. The electrical resistivity is measured with the standard four-probe method. From analysis of the measurements, it is concluded that heavy rare earth metals are subject to the effect of stabilization of the free path length of conduction electrons at values which might exceed the interatomic distance. (author)