Global Warming & Extreme Heat

This monograph examines extreme heat as a systemic consequence of global warming and argues that rising temperatures function as a powerful polycrisis force multiplier across public health, labor productivity, infrastructure, food systems, water resources, ecosystems, and economic development. Drawing on climate science, physiology, economics, and resilience planning, the report demonstrates how relatively modest increases in average global temperature can produce disproportionately large increases in the frequency, intensity, and duration of extreme heat events. Particular attention is given to wet-bulb temperature thresholds, human thermoregulatory limits, demographic exposure in vulnerable regions, urban heat island dynamics, and the growing risks faced by populations lacking access to effective cooling technologies. The analysis further explores the cascading impacts of extreme heat on agriculture, labor markets, critical infrastructure, air quality, wildfire risk, water availability, and ecological stability. It identifies significant inequalities in heat exposure and adaptive capacity, with low-income populations in rapidly growing regions facing the greatest risks. The study evaluates clean cooling technologies, passive architectural solutions, district cooling systems, and governance innovations such as heat-health warning systems and parametric insurance mechanisms as key adaptation pathways. The report concludes that thermal resilience will become a defining development and security challenge of the twenty-first century. It proposes a phased global roadmap centered on universal cooling access, resilient infrastructure, occupational protections, urban redesign, and climate-adaptive governance. Collectively, these measures are presented as essential for reducing mortality, protecting economic productivity, and sustaining human well-being in an increasingly warmer world. Based on this assessment, extreme heat should be understood not as an isolated environmental hazard, but as a foundational risk shaping the future habitability, stability, and prosperity of societies worldwide.