Embodiments of a heat-transfer mechanism are described. This heat-transfer mechanism includes a first heatpipe having a first end and a second end, and a second heatpipe having a third end and a fourth end. Moreover, a heatpipe coupler is thermally coupled to the second end of the first heatpipe and the third end of the second heatpipe. This heatpipe coupler includes a housing surrounding a cavity and a liquid metal contained within the cavity, thereby providing a thermal path from the first end of the first heatpipe, which is configured to couple to a condenser, to the fourth end of the second heatpipe, which is configured to couple to an evaporator.