The invention relates to an instantaneous air-heating unit. The invention comprises a hot air (2) intake hood (1) which is disposed partially against the exhaust gas collectors (3) of the engine (4) of the vehicle, preferably when the vehicle is being started. According to the invention, an air duct (5) connects the aforementioned hood to a small turbine (6) or an extractor which drives the air to the enclosure (8), the front and rear windows (9) or the outside rear-view mirrors (10) through one or more suitable ducts (7). Moreover, a thermostat (11) is used to shut down the instantaneous heating and start up the standard heating using a manual or electric butterfly valve (12), thereby stopping the turbine (6).