An electronics assembly, for example a computer that may be employed as a network server, has an enclosure, and a plurality of heat-generating components such as microprocessors located inside the enclosure. One or more fans may be provided for maintaining a through flow of air for cooling the components of the assembly. The heat-generating components are located within the enclosure in line with the direction of the flow of air, and the heat-sinks have a configuration such that the air flows over them in parallel. The heat-sinks may each have a flat base for mounting on the component, and a cantilevered portion having one end located on the base, and another end that extends beyond the base and over the base of the other heat-sink, but not in contact with it.