A cooled turbine blade having a base and an airfoil, the base including cooling air inlet and an internal cooling air passageway, and the airfoil including an internal heat exchange path beginning at the base and ending at a cooling air outlet at the trailing edge of the airfoil. The airfoil also includes a “skin” that encompasses a tip wall, an inner spar, a leading edge rib, and a leading edge air deflector. The leading edge rib is configured to form a leading edge chamber in conjunction with the leading edge of the skin. The leading edge air deflector is shaped and positioned such that cooling air leaving the leading edge chamber is both turned and diffused.