[Preparedness for summer illnesses and emergencies in Chile, 2024-2025: lessons from an innovative policyPreparação para doenças e emergências no verão de 2024-2025 no Chile: lições de uma política inovadora].

Climate change and the increasing frequency of extreme heat events have heightened the importance of health issues during the summer season. This season is also associated with greater population mobility, outdoor recreational activities, and exposure to biological and environmental risks, all of which require coordinated responses from health systems. Within this context, the Ministry of Health of Chile implemented the summer seasonal illness and emergency preparedness plan 2024-2025, with the goal of strengthening surveillance, intersectoral coordination, and risk communication in response to priority threats to population health.This article describes the design, implementation, and key results of this first national initiative to prepare for diseases occurring during the summer season. The strategy was based on a multilevel governance model that liaised between the central, regional, and local levels of the health system through national coordination meetings, integrated surveillance, strengthening of technical capacities, and public communications. During the season covered by the plan, detection of Aedes aegypti remained confined to areas where it was previously known to occur; 395 outbreaks of foodborne illnesses affecting 2618 people were investigated; 8 cases of hantavirus were reported, with no deaths; and environmental risks and emergencies were monitored, including 4330 forest fires, none of which affected health facilities.This experience demonstrates the feasibility of implementing integrated disease preparedness strategies during the summer season and provides lessons for their consolidation as public policy, including the formalization of coordination mechanisms, the systematic assessment of implementation, and the incorporation of new hazards, such as drowning and injuries associated with recreational water activities.