Just to elaborate a little on Fred's post, A turbulent boundary layer of a given thickness has much higher heat transfer than a laminar boundary layer. If you look at the heat transfer of a turbine airfoil section, the two worst points are at the leading edge and at the transition to turbulent boundary layer. My recolection is that the transition point actually has the higher heat load, even though the boundary layer is substantially thicker there.

 

Also, in radiators it is common to louver the fins in order to increase turbulence, and therefore heat transfer. The effect is much the same as adding turbulators ahead of the ailerons. Energy from the free stream is circulated down into the boundary layer where it can be used for heat transfer of control force.

 

Rob