Panel heater with temperature monitoring

A panel heater comprising:

• at least one flat substrate and
• an electrically conductive coating,
• wherein the electrically conductive coating extends at least over part of a substrate area and is electrically connected to at least two connecting electrodes provided for electrical connection to two terminals of a voltage source, such that by applying a feed voltage, a heating current flows in a heating field,
• wherein the panel heater is provided with one or more heating current paths and one or more measurement current paths, which are formed into the electrically conductive coating by coating-free separating regions and formed by the electrically conductive coating,
• wherein the one or more measurement current paths differ at least in sections from the one or more heating current paths, and
• wherein the one or more measurement current paths are thermally coupled at least to a portion of the heating field and have at least two connecting sections for connecting a measuring device for ascertaining an electrical resistance of the one or more measurement current paths.