A composition including 2,3,3,4,4,4-hexafluorobut-1-ene as a mixture with one or more hydrocarbon, hydrofluorocarbon, ether, hydrofluoroether or fluoroolefin compounds having a boiling point of less than or equal to 0° C. Also, the use of such a composition in heat transfer applications. Also, a heat transfer installation including a vapor compression circuit containing such a composition as heat-transfer fluid or containing a heat-transfer composition including such a composition, and also one or more additives chosen from lubricants, stabilizers, surfactants, tracers, fluorescers, odorous agents and solubilizers, and mixtures thereof.