In the JET Optimised Shear (OS) regime a combination of Lower Hybrid current drive, Ion Cyclotron Resonance Heating (ICRH) and Neutral Beam Injection (NBI) heating is used during the current rise phase to control the plasma current profile. Typically the high power heating phase is timed such that <~2.0, and if a power threshold is exceeded then an Internal Transport Barrier (ITB) forms [1]. This combination of relatively low core magnetic shear and high pressure gradients (at the ITB) represents the conditions in which magnetohydrodynamics (MHD) instabilities such as the infernal mode [2] would be expected to be destabilised.