Method for cooling at least one hot load on board a vehicle such as an aircraft including a heat-transfer fluid circulation fluid loop, wherein: - for each hot load to be cooled, a flow of said heat-transfer fluid, referred to as cold heat-transfer fluid flow, is introduced into a heat exchanger, referred to as first heat exchanger, of a first heat exchange device associated with the hot load so as to transfer calories therefrom to the heat-transfer fluid, cool the hot load and produce a flow of said heat-transfer fluid, referred to as hot heat-transfer fluid flow, at a temperature greater than that of said cold heat-transfer fluid flow, - at least a portion of said hot heat-transfer fluid flow from at least one such first heat exchanger is introduced into at least one heat exchanger, referred to as second heat exchanger, of a second heat exchange device arranged to be able to cool same with air outside the vehicle, - a flow of said heat-transfer fluid is introduced into at least one heat exchanger, referred to as third heat exchanger, of a third heat exchange device arranged to be able to exchange a heat flux between this flow of said heat-transfer fluid and at least one thermal store, separate from said heat-transfer fluid, on board the vehicle, - when cooling requirement criteria are met, at least one such third heat exchanger is fed according to a circulation mode, referred to as direct mode, wherein it receives, on a first orifice of this third heat exchanger, at least a portion of said hot heat-transfer fluid flow from at least one such first heat exchanger, said corresponding third heat exchange device transferring calories from this hot heat-transfer fluid to the thermal store so as to cool said heat-transfer fluid, the heat-transfer fluid thus cooled being delivered by a second orifice of the third heat exchanger, characterised by the step, wherein: - when said cooling requirement criteria are not met, at least one such third heat exchanger is fed according to a circulation mode, referred to as reverse mode, wherein it receives, on said second orifice of this third heat exchanger, a flow of said heat-transfer fluid and said corresponding third heat exchange device transfers calories from the thermal store to this heat-transfer fluid so as to cool this thermal store, and the heat-transfer fluid thus heated comes out of this third heat exchanger via said first orifice of this third heat exchanger and wherein the fluid loop is a diphasic loop. - for each hot load to be cooled, a flow of said heat-transfer fluid, referred to as cold heat-transfer fluid flow, is introduced into a heat exchanger, referred to as first heat exchanger, of a first heat exchange device associated with the hot load so as to transfer calories therefrom to the heat-transfer fluid, cool the hot load and produce a flow of said heat-transfer fluid, referred to as hot heat-transfer fluid flow, at a temperature greater than that of said cold heat-transfer fluid flow, - at least a portion of said hot heat-transfer fluid flow from at least one such first heat exchanger is introduced into at least one heat exchanger, referred to as second heat exchanger, of a second heat exchange device arranged to be able to cool same with air outside the vehicle, - a flow of said heat-transfer fluid is introduced into at least one heat exchanger, referred to as third heat exchanger, of a third heat exchange device arranged to be able to exchange a heat flux between this flow of said heat-transfer fluid and at least one thermal store, separate from said heat-transfer fluid, on board the vehicle, - when cooling requirement criteria are met, at least one such third heat exchanger is fed according to a circulation mode, referred to as direct mode, wherein it receives, on a first orifice of this third heat exchanger, at least a portion of said hot heat-transfer fluid flow from at least one such first heat exchanger, said corresponding third heat exchange device transferring calories from this hot heat-transfer fluid to the thermal store so as to cool said heat-transfer fluid, the heat-transfer fluid thus cooled being delivered by a second orifice of the third heat exchanger, - when said cooling requirement criteria are not met, at least one such third heat exchanger is fed according to a circulation mode, referred to as reverse mode, wherein it receives, on said second orifice of this third heat exchanger, a flow of said heat-transfer fluid and said corresponding third heat exchange device transfers calories from the thermal store to this heat-transfer fluid so as to cool this thermal store, and the heat-transfer fluid thus heated comes out of this third heat exchanger via said first orifice of this third heat exchanger and wherein the fluid loop is a diphasic loop.