The thermal lattice Boltzmann method (TLBM) with doubled-population is used to analyze the dilute magnetorheological fluid (MRF) flow and heat transfer performances in two-dimensional hot micro channels, by regarding the magnetic particles (MPs) as a quasi fluid. A method for calculating external forces on MPs is established in order to improve the computational accuracy and efficiency. It is revealed that with the increasing volume fraction of MPs, on lattice node, both the Van der Waals force and the magnetic dipole force increase but the Brownian force only randomly varies within a range which is three orders of magnitude smaller than magnetic dipole force. Simulations are carried out under both constant temperature and heat flux boundary conditions. The effects of channel length, inlet velocity and volume fraction of MPs on heat transfer performances are investigated and the results indicate that the dilute MRF behaves a better heat transfer performance than water even without the effect of external magnetic field. (C) 2016 Elsevier Ltd. All rights reserved.