Abstract: The thermal management system for in-slot cooling of electric motors includes separating structures, either in the form of a scaffolding structure or a monolithic winding structure which is placed in between the adjacent winding turns to physically separate the winding turns to define coolant fluid passages for circulation of a coolant fluid in direct contact with the lateral surfaces of the winding turns. The scaffolding and monolithic winding structures are made from an electrically insulating material and are filled with a dielectric fluid that serves both the coolant and the electrical insulator between the winding turns. An end-winding organizer may be positioned at two end regions of each stator tooth to provide a curved surface for the winding turns to be held in tension throughout the 180° winding end turns and is formed with grooves to define the passage for the coolant flow to ensure that the flowing coolant reaches the surface of the innermost winding turns.