In recent decades, sea surface temperatures and the occurrence of heat stress in coral communities have soared. High surface water temperatures lead coral populations to evict their symbiotic, and colorful, algal residents. The photosynthesizing algae are what feed the coral, and the process—known as bleaching—can eventually kill it, leaving parched white exoskeletons in place of formerly vibrant reefs. However, not all coral reefs seem equally affected by mass bleaching at the hands of global warming. Some processes, like deep water upwelling, are known to offset rising temperatures locally, butCarrigan and Puotinen investigate a novel mechanism that they suggest may be responsible for protecting some susceptible populations.