Lay fully self-adhesive mesh on top of an insulation board (either coated for timber or uncoated for concrete substrates).
Cover with a flexible tile adhesive if you're laying floor tiles, or cover with self-levelling compound if you're laying carpet and laminate flooring.
As the cable size for sticky backed mats is only 3.6mm in diameter, and foil mats for under laminates and carpet are 1.8mm, these ultra-thin mats do not require you to raise the floor level.