In this paper we develop a new high-order ghost-cell based Immersed Boundary Method (IBM) for flow and thermal simulation of multiphase flow system with moving bodies, based on our previous edition with only stationary boundary treatment. The newly developed approach is validated by comparing with earlier reported simulation and experimental results of both the pressure drag coefficient of a prescribed harmonic in-line oscillating sphere and the trajectory, velocity history of a free falling sphere under gravity and the rising of a spherical catalyst particle in an enclosure, using relatively coarse mesh resolution. Excellent agreement is obtained, demonstrating the accuracy and efficiency of our newly developed method. Finally, we employ the new method to investigate the cooling process of a freely settling spherical particle under gravity, aiming at revealing the impact of natural convection on particle cooling. It turns out that the heat transfer and hydrodynamics interaction is the most obvious when the Richardson number is the largest in our simulations. When the Reynolds number equals, the Nusselt number is always higher for the no buoyancy case than the case with buoyancy force. (C) 2015 Elsevier Ltd. All rights reserved.