Experiments with spherical particles sliding and rolling in cocurrent and counter-current directions over a heated wall have been conducted to study the mechanism of heat transfer in a turbulent flow carrying coarse particles. The detailed distribution of the local temperature and heat transfer coefficient in the vicinity of moving coarse particles was obtained. Results of experiments show the effect of the particle motion and rotation on the temperature distribution of the heated wall and on the heat transfer in the turbulent boundary layer. (C) 2001 Elsevier Science Ltd. All rights reserved.