A hair styling apparatus comprising a pair of closable jaws to engage a user's hair ; wherein said jaws have complementary shapes, a first said jaw defining a curved ridge having first and second sides coupled by a curved apex portion and a second said jaw defining a curved recess having first and second sides coupled by a curved base; wherein said first and second jaws are moveable from an open position in which a first hair contacting surface of said first side of said curved ridge and a second hair contacting surface of said second side of said curved ridge are spaced apart respectively from a first hair contacting surface of said first side of said curved recess and a second hair contacting surface of said second side of said curved recess, to a closed position in which said first hair contacting surface of said curved ridge is adjacent the first hair contacting surface of the curved recess and said second hair contacting surface of said curved ridge is adjacent the second hair contacting surface of the curved recess, whereby, in use, a section of hair is clamped between the contacting surfaces when the jaws are in the closed position; wherein the first and second sides of one or both of said first and second jaws includes a heater such that, when said jaws are closed, hair is heated in a first heating region between the first side of the curved ridge of said first jaw and the first side of the curved recess of said second jaw and in a second heating region between the second side of the curved ridge of said first jaw and the second side of the curved recess of said second jaw; wherein the curved apex portion of the curved ridge and the curved base portion of the curved recess define an insulated zone in which, when said jaws are closed, hair is not heated; wherein one or more projections are provided on one or both of said first and second jaws so that when the jaws are closed, said apex portion of said curved ridge of the first jaw is spaced apart from said curved base of the curved recess of the second jaw; wherein the first side of said second jaw has a curved longitudinal surface having a first active cooling region and the second side of said second jaw has a second curved longitudinal surface having a second active cooling region; wherein a transverse cross section through said second jaw defines a pair of S-shaped curves having a common forward curve into which said ridge of said first jaw fits, and linked to first and second respective reverse curves, said first and second reverse curves having the respective first and second active cooling regions on which hair may be cooled and curved; wherein said first heating region is located on said forward curve between said apex portion of the first jaw and the first active cooling region and said second heating region is located on said forward curve between said apex portion of the first jaw and the second active cooling region; and wherein said first active cooling region is located on said first reverse curve such that, when said jaws are closed, a tangent to a surface of engagement of the two jaws, at a point on said forward curve up to or at a point linking said forward and reverse curves avoids said first active cooling region. <EOS>