An assembly for treating gaseous emissions includes a substrate body having cells for the passages of emissions gas. Lengths of metal wire are located in selected ones of the cells and an induction heating coil is mounted adjacent the substrate body for generating a varying electromagnetic field. In this way the metal wires are heated, resulting in heating of the substrate body and heating of exhaust gas flowing in the cells. Individual lengths of wire or wire lengths that are joined together are configured as loop conductors.