Hyperthermia was the very first oncotherapy in human medicine. Despite its long history it has not achieved any breakthrough in clinical practices. The discovery of electromagnetism gave new hopes a century ago, however some controversies blocked its wide application. Oncothermia is a renewal, applying the synergy of the bioelectromagnetism with fractal physiology. Its basic approach makes selective energy absorption targeting the membrane rafts of the malignant cells. In this meaning this is a nanotechnology, treating the naturally present nano-particles (rafts) in 5 nm-range. The goal of the treatment is to induce apoptosis and drive the lost complex structure by possible re-synchronization of the autonomic malignant cells. The treatment tries avoid the constrains which induce unhelpful physiological reactions like the increase of the blood-flow which supports the tumor by nutrients and promotes metastatic processes. Oncothermia re-establishes the lost complexity of the malignant processes.