A thermal management system and method are presented for cooling an entity. The system comprises: a closed loop fluid flow line for flow of a coolant while being transferred in between its liquid and gas phases; at least one cooling zone located within the flow line and comprising at least one cooling interface; a vacuum generator unit operable for creating and maintaining vacuum condition at the cooling zone to thereby reduce evaporation temperature of the coolant located in the cooling zone; and a condensation zone spaced apart from the cooling interface downstream thereof with respect to a direction of the coolant flow from the cooling zone along the closed loop path wherein the coolant is condensed to liquid phase.