The invention provides a planar element which is intrinsically heatable and which is particularly suitable for attachment to multi-dimensionally curved surfaces. For this purpose the planar element features particularly high deformability, achieved in accordance with the invention through a planar element having a layer sequence comprising a heating layer and a contacting layer, each of these two layers being composed of a polymeric material based on elastomers and/or on plastic polymers which have a particular elongation at break and at the same time a particular tensile elasticity modulus. Furthermore, the invention provides an adhesively bonded assembly comprising a bonding substrate and a planar element of the aforesaid kind, a method of producing a planar element of the aforesaid kind, and the use of such a planar element for heating an adhesively bonded assembly.