A housing-less plate heat exchanger is provided for transferring heat between at least a first fluid and a second fluid. The heat exchanger includes a plurality of heat exchange plates stacked to enclose flow channels for the first and second fluids between the plates, a first intermediate plate pair sandwiched between a first and second stack of the heat exchange plates, and a barrier located between the plates of the intermediate plate pair to separate the first fluid from the second fluid. The intermediate plate pair includes a first fluid port extending laterally from the heat exchanger to transfer the first fluid between the heat exchanger and a device other than the heat exchanger. The intermediate plates are joined to enclose a first chamber, with the first chamber opening to the first fluid port and to a manifold for the first fluid to direct the first fluid between the first fluid port and the manifold.