Heat-Related Health Risks for People Experiencing Homelessness: A Rapid Review

This rapid review investigates the health and wellbeing implications of extreme heat events (EHEs) for people experiencing homelessness (PEH) in high-income countries. Recognizing that climate change is increasing the frequency and severity of extreme weather, the authors sought to update the literature published between January 2019 and May 2024. Using a rapid review design adhering to PRISMA guidelines, the researchers searched multiple databases including PubMed, Web of Science, and Scopus. Ultimately, 11 studies meeting strict inclusion criteria were synthesized narratively to identify key health impacts, vulnerability factors, healthcare utilization patterns, and barriers to resources.

The synthesis revealed five central themes regarding how extreme heat impacts PEH. First, vulnerability factors such as extreme age groups (younger adults and older adults) and pre-existing medical conditions significantly increase susceptibility to heat stress. Second, physical health impacts are profound, leading to elevated rates of heat-related morbidity, mortality, cardiovascular strain, and acute kidney injury. Third, extreme heat exacerbates mental health challenges and substance use disorders. Fourth, studies document a marked surge in emergency department visits among PEH during heatwaves, placing heavy burdens on healthcare systems. Finally, PEH face severe structural barriers, including water insecurity, social stigma, and physical or financial obstacles to accessing cooling centers.

As global temperatures rise due to climate change, extreme heat represents an escalating public health crisis. People experiencing homelessness are uniquely exposed and structurally underserved, meaning standard public health heat advisories are often insufficient for their needs. The insights from this review underscore the urgent necessity for structural policy changes—such as expanding stable, affordable housing—alongside inclusive, tailored emergency interventions like accessible cooling facilities with specialized support and reliable hydration access.