Described embodiments include a device, a method, and a system. A described device includes a closed-cycle heat transfer device. The device includes a hollow member configured to be thermally coupled with and to be disposed substantially parallel to a length of a live transmission line of an overhead power transmission system. The power transmission system is configured to transport electric power from one place to another. The device includes a working fluid contained within the hollow member and tuned to transport heat received from the live transmission line to a heat removal structure. The device includes the heat removal structure configured to dissipate the transported heat.