An airfoil (600; 700) for a gas turbine engine, the airfoil comprising: an airfoil body having a leading edge (606; 706) and a trailing edge (608; 708), a root region (610; 710) and a tip region (612; 712), wherein an aftward direction is from the leading edge toward the trailing edge and a radially outward direction is from the root region to the tip region; a forward-flowing serpentine flow path (602; 702) formed within the airfoil body, the forward-flowing serpentine flow path defined by a first serpentine cavity (618; 732), a second serpentine cavity (620; 720), and a third serpentine cavity (622; 722), wherein the first serpentine cavity is aftward of the second serpentine cavity, and the second serpentine cavity is aftward of the third serpentine cavity; a tip flag cavity (604; 704) extending aftward from proximate the leading edge to the trailing edge along the tip region of the airfoil body; and at least one shielding cavity (614, 616; 714, 716) located between a portion of the forward-flowing serpentine flow path and an external surface of the airfoil body, wherein the airfoil is configured such that a cooling air flow is supplied into the forward-flowing serpentine flow path from a serpentine inlet (624; 734) at the first serpentine cavity, and the cooling air flow passes through the first serpentine cavity, the second serpentine cavity, the third serpentine cavity, into and through the tip flag cavity, and exits through the trailing edge of the airfoil body, characterised in that the at least one shielding cavity comprises a first shielding cavity (614; 714) and a second shielding cavity (616; 716), and the first shielding cavity and the second shielding cavity are located on a pressure side of the airfoil body between the portion of the forward-flowing serpentine flow path and an external pressure side of the airfoil body, wherein the first shielding cavity and the second shielding cavity extend radially through the airfoil body from the root region to the tip region. an airfoil body having a leading edge (606; 706) and a trailing edge (608; 708), a root region (610; 710) and a tip region (612; 712), wherein an aftward direction is from the leading edge toward the trailing edge and a radially outward direction is from the root region to the tip region; a forward-flowing serpentine flow path (602; 702) formed within the airfoil body, the forward-flowing serpentine flow path defined by a first serpentine cavity (618; 732), a second serpentine cavity (620; 720), and a third serpentine cavity (622; 722), wherein the first serpentine cavity is aftward of the second serpentine cavity, and the second serpentine cavity is aftward of the third serpentine cavity; a tip flag cavity (604; 704) extending aftward from proximate the leading edge to the trailing edge along the tip region of the airfoil body; and at least one shielding cavity (614, 616; 714, 716) located between a portion of the forward-flowing serpentine flow path and an external surface of the airfoil body, wherein the airfoil is configured such that a cooling air flow is supplied into the forward-flowing serpentine flow path from a serpentine inlet (624; 734) at the first serpentine cavity, and the cooling air flow passes through the first serpentine cavity, the second serpentine cavity, the third serpentine cavity, into and through the tip flag cavity, and exits through the trailing edge of the airfoil body, characterised in that the at least one shielding cavity comprises a first shielding cavity (614; 714) and a second shielding cavity (616; 716), and the first shielding cavity and the second shielding cavity are located on a pressure side of the airfoil body between the portion of the forward-flowing serpentine flow path and an external pressure side of the airfoil body, wherein the first shielding cavity and the second shielding cavity extend radially through the airfoil body from the root region to the tip region.