Outdoor thermal comfort in K-12 schools: a systematic literature review

As children spend many hours outdoors for play, learning, and physical activity, the thermal quality of schoolyards has become an increasingly critical concern for public health and educational design, particularly under exposure to thermal extremes and climate change. This systematic review analyzes 35 peer-reviewed studies published between 2015 and 2025, identified through five online databases, to synthesize the current state of knowledge on outdoor thermal comfort (OTC) in K-12 schools. Findings show a strong focus on mitigating summer heat stress, particularly in primary schools within Mediterranean and humid subtropical climates. Most studies rely on field measurements combined with numerical simulations, typically using objective indices, while increasingly incorporating subjective measures such as behavioral adaptation. Across climates, vegetation and shading consistently emerge as the most effective mitigation strategies. By identifying research gaps, methodological trends, and dominant interventions, this review underscores the need for more comprehensive research on schoolyard thermal environments. It also provides practical guidance for architects, urban planners, and school administrators by outlining climate-responsive intervention priorities. Overall, this review highlights that improving outdoor thermal comfort in school settings is not merely an environmental design challenge but a cross-disciplinary issue at the intersection of public health, education, and climate adaptation. It calls for a shift from purely technical approaches toward integrated, participatory, and policy-oriented frameworks that position thermal comfort as a core component of school infrastructure.