Experimental investigation was performed on heat dispersion in the system composed of bed of porcelaine spheres between which sands were fluidized by an air stream. The system was heated by the wall of a tubular apparatus. The diameters of the spheres and the sand fractions as well as the air flow rates were varied in individual experiments. It has been found that the generation of the fluidized phase within the voids of the bed promotes the longitudinal uniformity of the local heat fluxes transferred from the hot apparatus wall into the system, as well as the radial uniformity of the temperature over the system cross-section. The flat radial temperature profiles within the bed with the fluidized phase manifest high effective thermal conductivity (practically indeterminable) which is responsible for very fast heat dispersion within the system. This is in contrast with the bed alone in which the well-marked radial temperature gradients manifest rather low effective thermal conductivity. The experiments revealed that the heat transfer rate from the hot apparatus wall into the organized fluidized system, like into the bed alone, is determined by the thermal resistance within the near-wall region of the systems. The Nusselt numbers expressing the heat transfer rates in both systems can be correlated with the Reynolds numbers by the same formula, independently of the sizes of the spheres and of the sands as well as of the fluidized phase density, in the range of gas flow rates applied in the experiments.