A heat exchanger including a first heat exchanger module with a first evaporator channel and a first condenser channel. The first evaporator channel and the first condenser channel are arranged in a first conduit. The first evaporator channel and the first condenser channel are fluidly connected to one another by a first upper distribution manifold and a first lower distribution manifold such that the first evaporator channel and the first condenser channel form a first loop for a working fluid. The first heat exchanger module includes a first evaporator heat transfer element and a first condenser heat transfer element. The heat exchanger includes a second heat exchanger module coupled to the first heat exchanger module by a fluid connection element for an exchange of the working fluid between the first heat exchanger module and second heat exchanger module.