An apparatus for controlling the temperature of a part of a human or animal body 2 during a cryosurgical procedure is disclosed. The apparatus comprises a radiative energy transmitter 26 for radiating energy to a zone of the body 2 to be protected from excessive cooling. There is also provided a means 12 for controlling the energy radiated by said radiative energy transmitter 26. Preferably the radiative energy transmitter comprises an infra-red laser diode coupled to a diffuser 34 by an optical fibre 40.
