This study investigates the thermal characteristics and irreversibility analysis of the combined electro osmotic and electromagnetic flow of a couple stress fluid through a microfluidic channel with constant wall heat flux boundary condition. The analytical solutions for electromagnetohydrodynamic (EMHD) flow velocity, temperature field and entropy production distribution are obtained using the physically relevant boundary conditions. Results show the effects of several factors, including couple stress parameter, Hartmann number, lateral/transverse electric field parameter and Brinkman number on the temperature transport and entropy generation, particularly, the details of how the temperature, Nusselt number and entropy generation vary with these parameters. The results demonstrate that the entropy generation in the channel is strongly dependent on the flow velocity and thermal energy distribution. In this analysis, the primary focus is placed on the impact of the couple stress parameter on EMHD flow velocity,heat transfer and entropy generation. The results reveal that when the couple stress physical parameter increases, the magnitude of temperature and Bejan number decreases. However, the Nusselt number and entropy productionrates have opposite effects towards the channel walls. The present research has enormous practical significance and can design efficient thermal micro/nanoequipment.