Heating = environmental sin ?

Hi together, it is forbidden in Germany to run its engine warm before the start already (noise pollution, exhaust gases). Regardless of that, it does not bring anything (cooling water we don’t warm up, heating does not work so fast, operating temperature is reached later). But – is a heater therefore OK? And – how do I explain this to my ignorant neighbor, who shows me about it (warning fee: 10€) and anyway has no idea of such modern things as standing heating (and internet forums) 😉 Tschau Torsten – der XC-Fan