Abstract: A passive cooling arrangement includes a primary hot-cooling circuit and a econdary convection cooling circuit. A condenser is arranged in the lower region of the convection cooling circuit. This condenser is provided for the medium of the hot-cooling circuit which is to be cooled down. A heat exchanger is arranged in the upper region of the secondary convection cooling circuit for cooling the coolant down by means of the ambient air. In order to prevent the condenser from freezing up in periods of frost which are of prolonged duration, the secondary convection cooling circuit includes means which, in the event of a reduction in the volume of the coolant due to falling temperature, effects a throttling or interruption of the flow of coolant through the heat exchanger. In this way the condenser cannot be cooled down any further.