A method of cooling a hydrocarbon feed stream (401, 501, 701) by indirect heat exchange with a first refrigerant stream (435, 535, 735) in a cooling heat exchanger (460, 560, 760) wherein the method comprises: a) compressing a warm low pressure first refrigerant stream (410, 510, 710) in one or more compression stages (412, 512, 712) to produce a compressed first refrigerant stream (413, 513, 713); b) cooling the compressed first refrigerant stream (413, 513, 713) in one or more cooling units (414, 514, 714) to produce a compressed cooled first refrigerant stream (415, 515, 715); c) introducing the compressed cooled first refrigerant stream (415, 515, 715) into a first vapor-liquid separation device (416, 516, 716) to produce a first vapor refrigerant stream (417, 517, 717) and a first liquid refrigerant stream (418, 518, 718); d) introducing the first liquid refrigerant stream (418/433, 518/533, 718/733) into the cooling heat exchanger (460, 560. 760); e) cooling the first liquid refrigerant stream (418/433, 518/533, 718/733) in the cooling heat exchanger (460, 560, 760) to produce a cooled liquid refrigerant stream (419, 519, 719); f) expanding the cooled liquid refrigerant stream (419, 519, 719) to produce a cold refrigerant stream (435, 535, 735), introducing the cold refrigerant stream into the cooling heat exchanger (460, 560, 760) to provide refrigeration duty required to cool the hydrocarbon feed stream (401, 501, 752), the first liquid refrigerant stream (418/433, 518/533, 718/733), and a second refrigerant stream (444, 544, 753); g) compressing the first vapor refrigerant stream (417, 517, 717) in one or more compression stages (421, 521, 721) to produce a compressed vapor refrigerant stream (422, 522, 722); h) cooling and condensing the compressed vapor refrigerant stream (422, 522, 722) to produce a condensed refrigerant stream (427, 527, 727); i) expanding the condensed refrigerant stream (427, 527, 727) to produce an expanded refrigerant stream (429, 529, 729); j) introducing the expanded refrigerant stream (429, 529, 729) into the first vapor-liquid separation device (416, 516, 716); k) introducing the second refrigerant stream (444, 544, 753) into the cooling heat exchanger (460, 560. 760); l) introducing the hydrocarbon feed stream (401, 501, 752) in the cooling heat exchanger; and m) cooling the hydrocarbon feed stream (401, 501, 752) in the cooling heat exchanger to produce a cooled hydrocarbon stream (402, 502, 702); and n) further cooling and liquefying the cooled hydrocarbon stream (402, 502, 702) in a main heat exchanger to produce a liquefied hydrocarbon stream; characterized in that the method further comprises, prior to performing step (d), cooling at least a portion of the first liquid refrigerant stream (418, 518, 718) by indirect heat exchange with at least a portion of the expanded refrigerant stream (429, 536, 729) in a first heat exchanger (430, 530, 730). a) compressing a warm low pressure first refrigerant stream (410, 510, 710) in one or more compression stages (412, 512, 712) to produce a compressed first refrigerant stream (413, 513, 713); b) cooling the compressed first refrigerant stream (413, 513, 713) in one or more cooling units (414, 514, 714) to produce a compressed cooled first refrigerant stream (415, 515, 715); c) introducing the compressed cooled first refrigerant stream (415, 515, 715) into a first vapor-liquid separation device (416, 516, 716) to produce a first vapor refrigerant stream (417, 517, 717) and a first liquid refrigerant stream (418, 518, 718); d) introducing the first liquid refrigerant stream (418/433, 518/533, 718/733) into the cooling heat exchanger (460, 560. 760); e) cooling the first liquid refrigerant stream (418/433, 518/533, 718/733) in the cooling heat exchanger (460, 560, 760) to produce a cooled liquid refrigerant stream (419, 519, 719); f) expanding the cooled liquid refrigerant stream (419, 519, 719) to produce a cold refrigerant stream (435, 535, 735), introducing the cold refrigerant stream into the cooling heat exchanger (460, 560, 760) to provide refrigeration duty required to cool the hydrocarbon feed stream (401, 501, 752), the first liquid refrigerant stream (418/433, 518/533, 718/733), and a second refrigerant stream (444, 544, 753); g) compressing the first vapor refrigerant stream (417, 517, 717) in one or more compression stages (421, 521, 721) to produce a compressed vapor refrigerant stream (422, 522, 722); h) cooling and condensing the compressed vapor refrigerant stream (422, 522, 722) to produce a condensed refrigerant stream (427, 527, 727); i) expanding the condensed refrigerant stream (427, 527, 727) to produce an expanded refrigerant stream (429, 529, 729); j) introducing the expanded refrigerant stream (429, 529, 729) into the first vapor-liquid separation device (416, 516, 716); k) introducing the second refrigerant stream (444, 544, 753) into the cooling heat exchanger (460, 560. 760); l) introducing the hydrocarbon feed stream (401, 501, 752) in the cooling heat exchanger; and m) cooling the hydrocarbon feed stream (401, 501, 752) in the cooling heat exchanger to produce a cooled hydrocarbon stream (402, 502, 702); and n) further cooling and liquefying the cooled hydrocarbon stream (402, 502, 702) in a main heat exchanger to produce a liquefied hydrocarbon stream;