Abstract: Climate change is driving an increase in the frequency and intensity of extreme heat events, leading to a rising incidence of heat-related illnesses (HRI) and placing significant strain on healthcare systems. The prehospital phase, managed by Emergency Medical Services (EMS), is a critical window for intervention, as rapid cooling is the primary determinant of survival for severe HRI like heat stroke. This scoping review synthesizes evidence on the efficacy of prehospital HRI management, the identification of vulnerable populations, and system-level adaptation strategies. Findings confirm that cold water immersion is the most effective cooling method for exertional heat stroke, while evaporative cooling is the most feasible and widely applicable technique across diverse settings. The burden of HRI disproportionately affects vulnerable groups, including the elderly, outdoor laborers, and socially marginalized populations, due to physiological, environmental, and socioeconomic factors. Effective management requires not only evidence-based clinical protocols but also the integration of EMS with public health heat warning systems, community paramedicine, and proactive, equitable outreach. Significant barriers to implementation include technological limitations, resource constraints, and fragmented inter-agency coordination. Future efforts must focus on standardizing protocols, enhancing training, and addressing research gaps through robust studies on cooling efficacy, cost-effectiveness of community interventions, and the long-term impact of adaptive strategies on patient outcomes.

Keywords: Heat-Related Illness, Prehospital Care, Emergency Medical Services, Climate Change, Vulnerable Populations.