Provided herein are an apparatus and methods to induce electromagnetic field in biologic tissue for thermal therapy. The apparatus comprises electromagnetic devices fitted to be releasably deployed inside a body, magnetic materials to be deployed in a body, and a magnetic centrifuge machine. An electromagnetic device includes a controllably flexible fiberoptic tubular device with a magnetic-flux-controlled electromagnetic assembly on its distal end. The electromagnetic device receives direct or alternating electric current. Implanted particulate magnetic materials in close proximity to said electromagnetic assembly form reversible magnetic vascular mold in target blood vessels by static magnetic field produced by direct electric current to said electromagnetic assembly. Implanted magnetic materials generate heat by alternating magnetic field induced by alternating electric current to said electromagnetic assembly. A magnetic centrifuge machine removes magnetic materials from blood by centrifugation under static magnetic field after completion of thermal therapy.
