Infrared vs electric
What makes an infrared heating pad different
A standard electric heating pad warms its surface with a wire and you feel heat where it touches. An infrared heating pad warms a layer of mineral stones (jade, amethyst, tourmaline) that emit far infrared; the heat is absorbed below the surface, so the pad feels gentler at the skin while the warmth goes deeper and lasts after you switch it off. Infrared pads run lower surface temperatures, which is why they are used for longer sessions and for lying on.
Negative ions (BioMat) come from tourmaline in the stone layer; low EMF (Therasage) means the heating element is shielded for close, daily use.