An experimental investigation was performed to study the effect of flow pulsations bk the local heat transfer characteristics of a planar air jet. A microsensor provided localized and essentially instantaneous heat flux and temperature signals. Heat transfer and thermal anemometry flow measurements were synchronized to associate influences of periodic flow structures and pulsations on heat transfer. Pulsation frequencies corresponded to Strouhal numbers below 0.106, and pulse amplitude was varied from 0 to 50% of the mean flow velocity. Nusselt numbers in the nozzle mid-plane increased by up to 12%, and by up to 80% at distances downstream.