PROJECT SUMMARY/ABSTRACT Heat waves cause a disproportionate number of deaths in the elderly relative to any other age group. Most of the hospitalizations and deaths in this population during heat waves are due to cardiovascular and renal complications linked to elevated thermal strain, and not directly due to hyperthermia per-se. Indoor cooling with an air conditioner remains the most effective strategy to prevent the deleterious health effects of heat waves. However, approximately 1 in 8 Americans do not have in-home air conditioners, and the rising household energy costs potentially makes air conditioning unaffordable for lower-income individuals. Also, power outages and industry/government-imposed rolling blackouts, along with COVID-19 related closures of public spaces, threaten region-wide access to air conditioning at times when it is most needed. Thus, there is a clear need to identify non-air conditioning dependent cooling modalities to attenuate excessive elevations in core body temperature and associated cardiovascular and renal stress in the elderly during heat wave conditions. The broad goal of this project is to test the efficacy of low-energy cooling strategies directed at mitigating the adverse thermal, cardiovascular, and potential renal consequences of heat wave exposure in the elderly. Aim 1 will test the hypothesis that skin wetting is an effective cooling modality to attenuate elevations in core body temperature and accompanying cardiovascular stress during heat waves in the elderly, while fan use may be detrimental depending on air temperatures and whether skin wetting is also employed. Aim 2 will determine if recognized impairments in thermoregulatory capacity and aging-related reductions in kidney function in the elderly will culminate in increased renal stress during heat wave exposures. The expected outcomes from this work will have a direct positive impact on the elderly by evaluating the efficacy of practical, low-energy cooling strategies that have the potential to save lives during heat waves. Further, we will provide critical information that comprehensively characterizes the extent of renal stress during simulated heat waves in elderly individuals. This research directly supports the mission of NIH in that we will uncover mechanistic physiological findings from human participants with the goal of translating these findings to guide individuals, caregivers, and communities on effective approaches to reduce heat related illness/injury. To ensure that this study was designed to maximize clinical relevance and my scientific training, I assembled a strong interdisciplinary clinical research/mentoring team consisting of expert integrative physiologists, physician-scientists, and a biostatistician. My primary goals during this fellowship are to complete the proposed project, master several technical skills (e.g., cardiac echocardiography, assessment of renal function/injury, etc.), improve my ability to obtain future extra...