Magnetic hyperthermia is beneficial in cancer treatment and in the treatment of some blood vessel diseases. However, excessive temperatures may also kill healthy cells in the vicinity of a sick cell. Using magnetic nanoparticles and changing the nature of the magnetic field as required, magnetic hyperthermia may be regulated in the blood. This research examines the effects of uniform and non-uniform magnetic fields on suspensions of bio-magnetic fluid and nano-bio-magnetic fluid under hyperthermia. Blood is a diamagnetic material, and when combined with superparamagnetic Fe3O4, its thermo-mechanical characteristics are changed significantly. By manipulating the nature of the magnetic field, it is possible to raise or decrease the temperature in the flow domain of magnetic nano-fluids. A computational study of two such magnetic fields has been conducted, and their effects on the blood-based magneto nano-fluid flow in a rectangular conduit have been documented in this study using COMSOL multi-physics. Results indicate that a uniform magnetic field increases temperature only locally, but decreases the overall temperature in the domain. The non-uniform field of a current-carrying wire decreases both the local maximum and average blood temperature as field strength increases.