Abstract: The invention relates to a device for heating flowing fluids, in particular intravenous fluids, comprising a fluid housing containing at least one fluid channel, through which the fluid can be conducted from an inlet of the fluid housing to an outlet of the fluid housing, a heating unit containing at least one electric flat heating element for heating the fluid flowing through the fluid channel, and a temperature control unit containing at least one temperature sensor arranged on the flat heating element, wherein the flat heating element is arranged inside the fluid housing, wherein the flat heating element at least partially forms a wall of the fluid channel, wherein at least one linear fluid channel extends between the inlet of the fluid housing and the outlet of the fluid housing.