The problem of heat transfer from a cylindrical pipe is formulated for a case where the flow inside the pepe consists of a periodic motion imposed on a fully developed steady laminar flow. It is shown that the velocity pulsations induce harmonic oscillations in temperature thus breaking the temperature field into a steady mean part and a harmonic part. The interaction between the velocity and temperature oscillations introduces an extra term in the energy equation which reflects the effect of pulsations in producing higher heat transfer rates.