The growing performance of processors and 3D memories has resulted in higher power densities and temperatures. Dynamic thermal management (DTM) policies for processor cores and memory have received significant research attention, but existing solutions address processors and 3D memories independently, which causes overcompensation, and there is a need to coordinate the DTM of the two subsystems. Further, existing CPU DTM policies slow down heated cores significantly, increasing the overall execution time and performance overheads. We propose CoreMemDTM, a technique for integrating processor core and 3D memory DTM policies that attempts to minimize performance overheads. We suggest employing DTM depending on the thermal margin since safe temperature thresholds might differ for the two subsystems. We propose a stall-balanced core DVFS policy for core thermal management that enables distributed cooling, decreasing overheads. We evaluate CoreMemDTM using ten different SPEC CPU2017 workloads across various safe temperature thresholds and observe average execution time and energy improvements of 14% and 36% compared to state-of-the-art DTM policies. © 2022 EDAA.