The study of Bingham–Papanastasiou fluids is conducted in lid-driven cavity with consideration of viscous dissipation. The upper and left wall of the cavity is cold while other walls are insulated. Numerical simulations are conducted to study the isotherms, temperature profile, local and average Nusselt number. The main focus of work is to analyze the behavior of heat transfer within trapezoidal cavity. The governing system of nonlinear dimensionless partial differential equations is analyzed by using PDE solver of finite element method in COMSOL. The analysis is carried out for different parameters like Reynolds number, Bingham parameter, stress growth parameter, Eckert number and Prandtl number. It is observed that impact of Bingham parameter on temperature variation is negligible while the impact of stress parameter leads to the reduction in temperature within cavity. The novelty of this work is that no work is done for the case of trapezoidal cavity where Bingham–Papanastasiou fluid behvior is observed under the considerationof viscous issipation and mixed convection.