A holistic approach to climate change in the emergency department: Direct impact of environmental factors on patients

Climate change is no longer a distant threat but a present and escalating burden on emergency departments (EDs) worldwide. Its direct and indirect effects, ranging from heatstroke and hypothermia to vector-borne disease resurgence and mass casualty incidents, challenge conventional models of emergency preparedness. This narrative review explores the intersection of climate dynamics with ED operational and clinical vulnerabilities. We summarize five core physiological mechanisms by which temperature extremes disrupt homeostasis and review high-risk medication classes that may exacerbate heat-related morbidity. In addition, we examine the World Health Organization's mass casualty triage framework and its relevance in climate-driven disasters such as floods, wildfires, and explosions. Special attention is given to low-resource settings and migration-heavy regions, where infrastructure strain and health inequity amplify the impact. We propose integrative, anticipatory planning models that combine clinical vigilance, environmental monitoring, and dynamic triage protocols. By identifying EDs as both front-line responders and sentinel systems, this study underscores the urgency of embedding climate resilience into emergency care strategies. Our synthesis aims to support clinicians, policymakers, and health systems in adapting emergency services to the realities of a warming world.