A cooling system particularly suitable for use on board an aircraft includes a cooling circuit allowing circulation of a two-phase refrigerant therethrough. An evaporator in the cooling circuit has a refrigerant inlet and a refrigerant outlet. A condenser in the cooling circuit has a refrigerant inlet and a refrigerant outlet. A detection device is configured to output a signal indicative of the state of aggregation of the refrigerant in a connecting portion of the cooling circuit which connects the refrigerant outlet of the evaporator to the refrigerant inlet of the condenser. A control device is configured to control at least one of the temperature and the pressure of the refrigerant in the connecting portion of the cooling circuit in dependence on the signal output by the detection device such that the refrigerant in the connecting portion of the cooling circuit is maintained in its gaseous state of aggregation.