The effect on heat transfer of a Rankine vortex located near a hat plate is studied analytically. The velocity field is a superposition of an inviscid, uniform flow and a secondary perturbation created by the vortex. Three different vortex configurations are analyzed : transverse, longitudinal and normal with respect to the plate. In general, an increase in the local heat transfer coefficient is observed in the downwash and a decrease in the upwash regions. The transverse vortex leads to a larger increase than the longitudinal configuration. The normal vortex has a slight decrease in the heat transfer.