An apparatus manipulates the shape of hair using dielectric heating. Typically,the apparatus includes opposing first and second electrodes respectively provided on first and second arms that are movable towards and away from one another. Drive circuitry supplies electrical energy to the first and second electrodes, to cause an alternating electric field to be produced in the vicinity of the electrodes in use, and thereby cause dielectric heating of hair placed between the electrodes in use. Sensing circuitry senses a change in coupling of energy from the alternating electric field to the hair during heating of the hair. Control circuitry controls the drive circuitry to vary the electrical energy supplied to the first and second electrodes in dependence upon the sensed change in coupling. A related method manipulates the shape of hair using dielectric heating.