In some respects, concepts disclosed herein generally concern systems, methods and components to detect a presence of a liquid externally of a desired primary flow path through a segment of a fluid circuit, e.g., throughout a cooling loop. Some disclosed concepts pertain to systems, methods, and components to direct seepage or leakage of a liquid coolant toward a lead-detection sensor. As but one example, some disclosed liquid-cooled heat exchangers incorporate a leak-detection sensor, which, in turn, can couple with a computing environment that monitors for detected leaks, and, responsive to an indication of a detected leak, invokes a task to control or to mitigate the detected leak.