Using previously-defined effective thermal conductivities for structural unit cells, a custom thermal-management structure has been developed for a powered ankle-foot orthosis. The structure provides the requisite personal safety for wearable medical devices. Minimal mass was achieved through the employment of these unit cells. Fabrication of the resultant structure is made practical by additive manufacturing. Results of the virtual testing are reported, as well as the preliminary results of an energy-based comparative-performance analysis of natural versus forced convection. Future work includes the integration of phase-change materials and thermoelectric generators.