A method and device for inducing anaesthesia in mammals by the application of RF energy to create hyperthermia derived neural anaesthesia. An RF generator drives a plurality of electrodes placed in tissue surrounding the target nerve fiber to desiccate the desired length of nerve fiber to be desiccated in a single deployment. The device allows high-speed selection/de-selection of bipolar electrode pairs or sets under continuous RF excitation. Activation of electrode pairs is adapted in response to sensed current density and temperature (by electrodes not in the current discharge activation phase) in order to create lesions of complex and well defined shape necessary for the production of hyperthermia derived neural anaesthesia.