Abstract: A heating and cooling system is disclosed for a motor vehicle powered by a water-cooled internal combustion engine wherein the engine radiator is mounted inside a housing, and the air flowing into the occupant compartment is caused to pass through said radiator. When the engine is hot, the radiator transfers heat to the air stream flowing into the compartment. A heat exchanger is mounted upstream of the radiator and is adapted to heat the air before it passes through the radiator. By virtue of this arrangement, the heat exchanger assists in raising the temperature of the engine cooling water and thus the engine at a rapid pace. The arrangement also provides that warm air for heating the vehicle interior is available shortly after starting of the engine to prevent fogging of the windows prior to engine warm up.