A conditioning apparatus (CA; CAE) for an engine comprising: - a conditioning device for cooling a medium to a plurality of temperature levels, said conditioning device having a first opening for receiving the medium at a first temperature level and a second opening to release the medium at a second temperature level lower than the first temperature level; - a delivery line connected to the second opening to bring the medium in thermal contact with the engine at a heat exchange region and comprising first adjusting means to control a first flow of the medium from the second opening toward the heat exchange region; - a return line connected to the first opening to supply the conditioning device with the medium brought in thermal contact with the engine at the heat exchanging region; and - a charge air cooler for cooling an intake air flow of the engine by means of the medium; wherein the conditioning device has a third opening to release the medium at a third temperature level lower than the second temperature level, said apparatus comprising an additional line to conduct the medium from the third opening to the return line; the additional line passing through the charge air cooler and comprising second adjusting means (T2; T4) to control a second flow (B1; B1, C2) of the medium from the third opening toward the charge air cooler, the conditioning apparatus (CA, CAE) further comprising a first bypass line that connects the return line to the delivery line, such that the medium flowing through the return line is allowed to bypass the conditioning device; wherein said first adjusting means comprise a first flow regulating device configured to control said first flow and a third flow of the medium through the first bypass line, characterised in that the delivery line comprises a first branch (DL3; DL2) connecting to the additional line upstream of the charge air cooler according to the direction of the second flow (B1; B1, C2); and wherein said second adjusting means (T2; T4) comprise a second flow regulating device configured to control the flow of medium from the third opening to the charge air cooling device and a fourth flow of the medium from the first branch (DL3; DL2) to the air charge cooler. - a conditioning device for cooling a medium to a plurality of temperature levels, said conditioning device having a first opening for receiving the medium at a first temperature level and a second opening to release the medium at a second temperature level lower than the first temperature level; - a delivery line connected to the second opening to bring the medium in thermal contact with the engine at a heat exchange region and comprising first adjusting means to control a first flow of the medium from the second opening toward the heat exchange region; - a return line connected to the first opening to supply the conditioning device with the medium brought in thermal contact with the engine at the heat exchanging region; and - a charge air cooler for cooling an intake air flow of the engine by means of the medium; wherein the conditioning device has a third opening to release the medium at a third temperature level lower than the second temperature level, said apparatus comprising an additional line to conduct the medium from the third opening to the return line; the additional line passing through the charge air cooler and comprising second adjusting means (T2; T4) to control a second flow (B1; B1, C2) of the medium from the third opening toward the charge air cooler, the conditioning apparatus (CA, CAE) further comprising a first bypass line that connects the return line to the delivery line, such that the medium flowing through the return line is allowed to bypass the conditioning device; wherein said first adjusting means comprise a first flow regulating device configured to control said first flow and a third flow of the medium through the first bypass line, characterised in that the delivery line comprises a first branch (DL3; DL2) connecting to the additional line upstream of the charge air cooler according to the direction of the second flow (B1; B1, C2); and wherein said second adjusting means (T2; T4) comprise a second flow regulating device configured to control the flow of medium from the third opening to the charge air cooling device and a fourth flow of the medium from the first branch (DL3; DL2) to the air charge cooler.