Proposing the Heat Illness–Homeless Exposure Assessment Tool (HI-HEAT) as a Tool for Risk Stratification for Persons Experiencing Homelessness During Extreme Heat Events

People experiencing homelessness face heightened risk of heat-related illness owing to chronic health conditions, medication use, and limited access to water, rest, and shade. This article introduces the Heat Illness–Homeless Exposure Assessment Tool (HI-HEAT), developed to support risk assessment and triage during extreme heat. The tool synthesizes physiologic, behavioral, and environmental risk factors into a structured checklist. Individuals are categorized as low, moderate, or high risk to guide intervention. HI-HEAT is intended for use by clinicians and outreach teams. Although further validation is needed, this tool addresses a critical gap in care for a vulnerable and underserved population.