Beyond proximity: Uncovering accessibility inequities in Barcelona’s climate shelters network for the summer of 2023

• Climate shelters are public urban facilities that provide protection from extreme heat, particularly for older adults. • Barcelona’s climate shelter network shows significant economic, temporal and spatial disparities, with nighttime and August availability being critically limited. • Socioeconomic and age-related vulnerabilities intersect, amplifying heat exposure. • Outdoor and nature-based shelters play a crucial role in maintaining equitable access, especially when indoor facilities are closed. • Age-friendly planning and targeted operational strategies are essential to enhance the effectiveness and inclusivity of climate shelters. Over the past decade, climate shelters networks have been implemented in various cities worldwide, particularly in areas where the Urban Heat Island effect exacerbates the impact of heat waves. These networks aim to provide thermal comfort and, crucially, to reduce heat-related mortality among vulnerable populations, such as the elderly. However, effective implementation of such networks requires more than merely identifying shelters -it demands strategic planning to ensure true accessibility for at-risk groups. This study evaluates the accessibility of the Climate Shelters Network proposed by the Barcelona City Council during the summer months of 2023 (July and August), focusing specifically on the elderly population due to their heightened vulnerability to heat stress. Accessibility was assessed through three main dimensions: economic (payment), temporal (daily and seasonal operation) and spatial (proximity). Data were sourced from open datasets, fieldwork and direct communication with municipal authorities and shelter facilities. Geographic analysis was conducted using QGIS to define service areas and pedestrian accessibility was measured based on a 6-minute walking threshold under conditions of strong and very strong heat stress, assuming an average walking speed of 3.42 km/h for elderly people. While official municipal data claimed that 97 % of the population was within a 10-minute walking distance of a shelter in this time period, our findings reveal that real accessibility varied depending on the month, day of the week and time. In the worst-case scenario at night, when only a limited number of shelters were open, coverage dropped to 15 % of the total elderly population living in the municipality of Barcelona. This study highlights the importance of incorporating dynamic variables into the planning and management of urban climate adaptation strategies, particularly those intended to safeguard vulnerable populations during extreme heat events.