Abstract: An apparatus and method for shipping a high value liquified gas product using a low value liquified gas product as a cooling medium, the low value liquified gas product having a boiling point lower than the high value liquified gas product, the high value liquified gas product being contained in a first vessel, the low value liquified gas product being contained in a second vessel, which is contained within the first vessel, the second vessel being in heat exchange relationship with the low value liquified product contained in the first vessel whereby heat conducted to and absorbed by the high value liquified product is expended as heat of vaporization of the low value liquified product, thereby maintaining the volume of liquified high value product substantially constant and preventing expensive losses through vaporization thereof.