Report via The Adrienne Arsht-Rockefeller Foundation Resilience Center – The United States has historically faced periods of extreme heat, but climate change over the next 30 years could make these events more frequent, widespread, and severe. Under prevailing late-twentieth-century climate conditions, around 5 percent of the current population—roughly 16.5 million people—could expect to  experience 100+ days per year where the daily maximum temperature is above 90°F. Without concerted action to limit emissions, this could increase to around 30 percent of the population by 2050. Many more people face extreme heat in unusually warm years: the recent heat wave in the Pacific Northwest provides stark evidence of how even relatively cool parts of the country can be exposed  to high-severity heat events. The economic and societal consequences of extreme heat are pervasive. Impacts encompass reductions in GDP, as workers and infrastructure systems become less  productive, as well as wider detrimental effects on well-being, as healthcare outcomes worsen and people are unable to access outdoor space. Impacts include transitory ones, from people enduring uncomfortable conditions and workers taking sick leave, and enduring losses, for example, due to interruptions to education or property damage from wildfires which can be more severe due to extreme heat’s effect on the environment. Tourism and other leisure activities are also affected as temperatures rise, making walking, shopping, and sightseeing uncomfortable and potentially dangerous. This paper quantifies some of the likely socioeconomic  impacts of heat in the United States under current and  possible future conditions. It provides new, quantitative evidence of the economic importance of heat for policy makers and investors and shows how impacts are disaggregated across regions, socioeconomic groups, and sectors of the economy…”