An information processing system includes: a processor; a memory; an input/output subsystem; and a bus coupled to the processor, the memory and the input/output subsystem. The system further includes a cooling structure for cooling the processor. The cooling structure consists of: a compressible backing; a plurality of rigid copper elements disposed between the backing and the processor; a first conformable heat-conducting layer disposed over the processor; a second conformable heat-conducting layer disposed between the compressible backing and the rigid elements; a liquid coolant; and a seal for containing the liquid coolant.