Classroom Heat Exposure, Lesson Timing and Learning Outcomes in Rural Namibian Primary Schools: An Integrative Narrative Review and Field Evaluation Framework

Classroom heat can undermine the conditions needed for learning even when schools remain open. This review examines how indoor temperature, lesson timing, ventilation and task difficulty should be considered together when evaluating learning outcomes in rural Namibian primary schools. A targeted narrative search identified classroom intervention studies, longitudinal achievement analyses, recent Southern African environmental and health studies, and climate education reports. Evidence was organised by exposure measurement, outcome type and relevance to naturally ventilated schools. Experimental findings support improvements in the speed of some school tasks under cooler conditions, whereas longitudinal studies associate repeated hot school days with weaker learning. However, these outcomes are not interchangeable, and available evidence does not establish a universal classroom temperature threshold or the effectiveness of low-cost adaptations in rural Namibia. A field evaluation framework is therefore developed around continuous environmental monitoring, equivalent short assessments, delayed retention tests and balanced allocation of lessons across time periods. Candidate adaptations include external shade, context-sensitive ventilation and timetable changes that preserve instructional time. The analysis emphasises confounding by clock time, task difficulty, attendance and classroom characteristics, and separates total intervention effects from changes mediated through temperature. Locally evaluated combinations of building and teaching adaptations could support climate-resilient education, but their learning benefits, affordability and equity implications require prospective testing.