A deterministic vortex method is extended to solve the connective transport phenomena of a two-dimensional impulsively started lid-driven flow in a square open cavity by including the energy equation. Of particular interest in the present study were the effects of Reynolds number and Prandtl number on the time-dependent flow field and temperature distribution in the cavity. Numerical results are presented to show the evolution of vortices and their effect on the heat transfer distributions over the cavity surface. A correlation is provided between Nu¯, Re, and Pr at H1, W = 0.2 for the steady state solutions.