The invention relates to a plate heat exchanger with a plate packet including a plurality of heat exchanger plates, which are stacked onto each other. The heat exchanger plates form first plate interspaces for a first medium and second plate interspaces for a second medium. The plate package has a space which is disposed inside a first inlet and a first outlet. Structure is arranged for creating, for each of the first plate interspaces, an inlet opening for the first medium from the space into the first plate interspaces and an outlet opening for the first medium from the first plate interspaces to the space.