Abstract: An arrangement for heating the operator's cabin of a machine driven by an internal combustion engine utilizes the engine oil as a heating medium as it is pressurized by a hydraulic pump and is elevated in temperature as it passes through a throttling element. To accelerate the heating of the internal combustion engine, the return line from the space heat exchanger into which the heated engine oil flows is located upstream of the engine lubricating points. To increase the heat supply to a portion of the engine oil, the hydraulic pump located downstream of the lubricating-oil feed pump suctions away, for the purpose of limiting the flow, some of the engine oil flowing through the main oil distribution system of the engine.