PROJECT SUMMARY The world is already 1.2 oC warmer now than in the second half of the 19th century. The Intergovernmental Panel on Climate Change (IPCC) predicts that we will cross a 1.5 oC increase in the coming decades. While the health impacts of climate change affect everyone, some groups are at higher risk for the associated health burden, particularly racial/ethnic minority or low income persons. This is one pathway through which climate change could exacerbate existing issues of environmental justice. The vast majority of previous studies on how weather impacts health, and these relationships under climate change, have focused on urban areas, however such impacts could differ in rural areas, which have different weather patterns, greenspace, and populations. Limited research suggests that racial health disparities may be larger in rural areas than in urban settings. The National Institute on Minority Health and Health Disparities (NIMHD) and NIH recognize rural populations, and people of color in rural areas in particular, as critical health disparities populations. The parent R01 investigates how weather and air pollution affect risk of hospital admissions and adverse birth outcomes in Virginia and West Virginia, with a focus on environmental health disparities. In particular, we investigate differences in these exposures and in associated health responses by several individual- and community-level characteristics including urbanicity (e.g., different impacts for rural vs. urban populations), race/ethnicity, socio-economic position, and other factors. Heat and heat waves are impacted by climate change, with overall higher temperatures and heat waves that occur more frequently, last longer, and burn hotter. This Administrative Supplement would estimate health burdens of heat and heat waves in the future, under specific climate change scenarios, including by subpopulation (e.g., by urbanicity, race/ethnicity), thereby providing critical evidence on public health burdens from climate change. The work is transdisciplinary, combining expertise in epidemiology and atmospheric science, with state-of-the-science meteorological and climate change modeling. We would estimate health risks from heat and heat waves under a changing climate for multiple scenarios reflecting different greenhouse gas and energy emissions scenarios. These findings can aid decision-makers, from communities to government officials, on issues such as heat action plans and decisions related to the built environment (e.g., green cities to alleviate the urban heat island effect). We will generate maps of changes in exposures under climate change that will be made publicly available. Also, when we have completed analysis our estimates of heat and heat waves under climate change will be made publicly available to benefit the broader scientific community and facilitate additional studies on climate change and health. This work lays the foundation for future research on climate cha...