Here, we leverage the temperate stony coral, Astrangia poculata, which naturally exhibits a facultative symbiosis with Symbiodiniaceae, thereby allowing for explicit examination of how thermal challenges influence coral hosts in isolation from their symbionts. Aposymbiotic A. poculata were collected from Woods Hole, the northern range limit for this species. These corals were thermally challenged in two independent common garden experiments (Heat challenge: 31oC, 10 days Cold challenge: 6oC, 16 days) to determine the effects of divergent thermal stressors.