Electromagnetic fields are created as a result of alternating current (AC). The Biomat uses direct current (DC) produced by converting household alternating current (AC) through a 5-tier buffering system. That is why EMF does not register on the Biomat. An electric blanket or typical heating pads use 60Hz alternating current (AC) running through wires. That creates an electromagnetic field in those devices. Beware of fake Biomats. They often have EMF.