An electronic apparatus comprising a housing having a plurality of electronic components and two or more separate heat transfer systems each thermally communicating with different one or more of said electronic components is characterized by at least one central heat transfer bus communicating with the two or more heat transfer systems, one or more switching or modulating connections between the heat transfer bus and one or more of the heat transfer systems, and one or more activating components for switching or modulating the one or more connections in response to monitored thermal load or temperature of the electronic components and/or heat transfer bus. Heat transfer between said heat transfer bus and one or more of the heat transfer systems is modulated or switched on or off by the activating components.