System method and apparatus for accurately carrying out the in situ heating of a targeted tissue. Small implants are employed with the targeted tissue which exhibit an abrupt change of magnetic permeability at an elected Curie temperature. The permeability state of the implant is monitored utilizing a magnetometer. The implants may be formed as a setpoint temperature determining component combined with a non-magnetic heater component to enhance the tissue heating control of the system. With the system, a very accurate quantum of heat energy can be supplied to a neoplastic lesion or tissue carrying infectious disease so as to maximize the induction of heat shock proteins. The system also may be utilized in conjunction with non-magnetic arterially implanted stents for the hyperthermia therapy treatment of restenosis and in conjunction with the mending of boney tissue.