the heater starts in rostock and starts in dresden

were driving on Sunday to dresden ds here from rostock almost 400 km…the heater runs and runs and runs and heats up the warm engine and consumes expensive diesel senselessly… who builds such a crap… after a pee break that was just before dresden he then did not jump on… do I actually have to go down from the highway so that the heater goes off? the other day someone had answered because of this topic but then no more…he had contacted the bosch service was e can the heater be switched off at a certain motor temperature… who had such a thing installed in them? lg the schmusis