Under the framework of the Urban Innovative Actions program of the European Commission, in 2020, 11 primary schools in Barcelona were transformed into climate shelters by implementing green, blue, and grey measures. Schoolyards were also opened to the local community to be used during non-school periods. Here we present the study protocol of a mixed-method approach to evaluate the effectiveness of the interventions in terms of improving environmental quality and health for users. We evaluated school level through the following: (1) quantitative pre-post quasi-experimental study, and (2) qualitative evaluation. The quantitative study included measures of (a) environmental variables (collected via low-cost and non-low-cost sensors), (b) students’ health and well-being (collected via health questionnaires, attention levels test, and systematic observations), and (c) teachers’ health and well-being (collected via thermal comfort measurements and health questionnaires). The qualitative methods evaluated the perceptions about the effects of the interventions among students (using Photovoice) and teachers (through focus groups). The impact of the interventions was assessed at community level during summer non-school periods through a spontaneous ethnographic approach. Data collection started in August 2019 and ended in July 2022. The evaluation provides the opportunity to identify those solutions that worked and those that need to be improved for future experiences, as well as improve the evaluation methodology and replication for these kinds of interventions.

Objectives: This study explores the use and perceptions of thermal comfort and wellbeing among the local community in the schoolyards in Barcelona that had been transformed into accessible climate shelters.Methods: We conducted a qualitative evaluation through a spontaneous ethnographic approach, combining 22 non-participant observations in the 11 transformed schoolyards with brief spontaneous interviews with 76 users and 18 caretakers who supervised the schoolyards during non-school days (June–July 2022). We conducted a thematic content analysis. We analyzed user characteristics, thermal comfort and wellbeing, activities and differences by age and gender, social behavior, additional benefits, and areas for improvement.Results: Adapted schoolyards were mostly visited by families and groups of adolescents with a higher proportion of boys. Participants reported that shade provided coolness and comfort, vegetation offered pleasant and naturalized environments, and water features were enjoyed for their cooling capacity and play opportunities. Schoolyards were mainly used as places for outdoor recreation and socialization.Conclusion: This study provides policymakers with evidence to support the transformation of schoolyards into climate shelters, creating comfortable outdoor recreational areas for the surrounding urban community.