State of the art hard disk recording heads use magnetic fields to encode data as magnetization on small sectors on a recording medium. A new generation of recording heads, called heat-assisted magnetic recording (HAMR), employs an additional nanoscopic heat spot to reduce the coercivity of a single recording bit on the recording medium. The development of the device hinges on suitable sensors for the nanoscale characterization of the produced heat. Nitrogen-vacancy (NV) defect centers in diamond could be a suitable candidate for this task. In addition to being efficient magnetometers that can be used to survey the magnetic field of recording heads, they are also sensitive to temperature changes. On the other side, hard disk recording heads can be used to efficiently control individual spins in nanoscale networks.