It is proposed a thermal management system for a fuel cell vehicle comprising: a first cooling circuit filled with a first coolant, having at least a first pump, a second cooling circuit filled with a second coolant, having at least a second pump, a third cooling circuit filled with a third coolant, having at least a third pump, wherein the first, second and third cooling circuits are fluidically independent from one another, wherein there is provided at least a selective heat exchanger arrangement, for selectively coupling thermally the third cooling circuit with the first cooling circuit and/or with the second cooling circuit, under predefined conditions.

A method and system are provided and include determining a sensed condition. When the sensed condition is below a first threshold and above a second threshold, the second threshold being less than the first threshold, a flow of coolant is started in a coolant loop comprising a first portion of a first heat exchanger. A flow of refrigerant is started in a refrigerant loop by starting a compressor within the refrigerant loop at a first speed.