Experiments are performed on the effects of a turbulent boundary layer on surface pressure and heat transfer, using a cylindrical model fitted with a variety of flares at Mach 5. The flow over compression corners of up to 20° (below the expected incipient separation value) is examined. Liquid crystal thermography indicates an unexpected peak in heat flux close to the corner. It is suggested that this is due to a small scale separation occurring earlier, i.e. at smaller corner angles, than previously observed. An estimate of the size of such a separation bubble is made and it is suggested that this is a predominantly laminar phenomenon.