A method of preheating a hybrid vehicle including storing reserve coolant in an insulated reservoir fluidly coupled to a coolant circuit of an engine of the hybrid vehicle; powering a fluid pump fluidly coupled to the coolant circuit with a power source external to the hybrid vehicle; pumping line coolant through the coolant circuit with the fluid pump; powering a heater thermally coupled to the coolant circuit with the power source external to the hybrid vehicle; heating the line coolant with the heater as the line coolant is pumped through the coolant circuit to increase a temperature of the line coolant; and mixing the line coolant with the reserve coolant to accelerate preheating of at least the engine of the hybrid vehicle.

System (10) for cooling an electric motor (12) of a vehicle with a hybrid motor comprising an electric motorization system (12) and an internal combustion motorization system (11), the internal combustion motorization system (11) comprising at least one fluid circulation circuit, characterized in that the system comprises a heat storage tank (14), in that said tank is connected to the fluid circulation circuit and to the electric motorization system via heat pipes (20).