A three-dimensional thermal hydraulics study is carried out for the Intermediate Heat eXchanger (IHX) of Sodium Cooled Fast Reactors (SFRs). IHX, a counterflow heat exchanger, exchanges heat between primary and secondary sodium. The coolant flow pattern into the IHX tubes is governed by the flow distribution device in the bottom header of the IHX. The desired flow distribution of the secondary coolant into tubes results in uniform temperature at tube outlets. Both hydraulics and thermal aspects are analyzed towards the investigation of the thermal gradient across various IHX internals. The temperature drop across bottom tube sheet, thermal shields, and outer and inner shells are investigated for different operating conditions of a typical SFR. Among all the operating conditions, it is observed that the temperature gradient across solid internals in IHX is negligible and ensures it's safe operation.