A method for vaporizing and heating a cryogenic fluid such as a liquefied natural gas, to a desired temperature in the ambient temperature range. The method comprises using an intermediate heat exchange fluid such as propane to heat the liquefied natural gas and to utilize the cold potential of the liquefied natural gas to produce power. The heat exchange fluid is heated by a heat source, such as warm or hot water available from an industrial process. The heat exchange fluid is pressurized and heated to form a heat exchange vapor. The heat exchange vapor is split into multiple streams that exchange heat with the cryogenic fluid in series fashion so that the cryogenic fluid is vaporized and heated to the desired temperature in stages using a common heat exchange fluid and heat source.