This session focuses on the concept of extreme heat events, specifically how high temperature coupled with humidity (wet-bulb temperature extremes) exponentially increases heat-related health impacts and mortality risk. Recent research indicates that oppressive (high-humidity, high-temperature) heatwaves may increase sharply with overshoot, up to five- to eight-fold under 1.5 °C to 2 °C warming. Understanding these trends is critical to adaptation planning, early warning systems, and health policy, especially in vulnerable regions. Presentations are invited on modeling projections of potentially lethal heat events, under future climate scenarios, and on methodologies to quantify associated health impacts, from heat-related mortality to compromised labor productivity and disease vulnerability. The session welcomes rigorous climate modeling studies, epidemiological analyses, and datasets that map extreme heat thresholds or events, especially those grounded in human thermoregulatory physiology. We also encourage contributions that analyze urban–rural differences, compounding effects with air pollution or disease outbreaks, inequities in vulnerability, adaptation limits, and health system implications in overshoot scenarios. By bringing together climate scientists, health researchers, urban planners, and policymakers, this session aims to highlight urgent, interdisciplinary challenges at the intersection of heat extremes and human health in a warming world.