The invention refers to a vehicular fluid heater. The invention particularly refers to an automotive water heater comprising at least one heat exchanger (8), at least one electrically operated heating unit (9) and at least one control unit for controlling power supply to the heating unit (9), the heat exchanger (8) comprising at least one thermally conductive body defining at least one fluid channel (15) for the fluid to be heated, the heating unit (9) being attached to a heat conductive surface of the heat exchanger (8). The vehicular fluid heater according to the invention has a control unit which is thermally connected to the heat exchanger (8) by a thermally conducting metal strip (30).