Rising air temperatures and intensification of heat stress in warm climates have seriously affected school open spaces, especially during school hours. This research evaluates the effect of pocket parks with different vegetation cover levels on microclimate and thermal comfort of school open spaces in a Mediterranean climate with hot, dry summers (Csa). Five design scenarios were defined: a baseline without green intervention and four incremental scenarios with different vegetation densities, analyzed using ENVI-met 5.6.1. Air temperature (Ta), mean radiant temperature (MRT), PMV, UTCI, and SET were selected as evaluation criteria.



The results show that in the baseline scenario, peak MRT (above 71°C), PMV (up to +6.8), UTCI (about 50°C), and SET (over 43°C) indicate severe to very severe heat stress during midday. The limited green space in scenario 2 (low density) had no noticeable effect on thermal indices compared to the baseline. In contrast, scenarios with more extensive vegetation (scenarios 3 to 5) showed a significant reduction in MRT and consequently improved combined thermal comfort indices, with reductions of 0.5–2°C in air temperature, 2–4°C in SET, and about 0.5–1 unit in PMV during critical hours compared to the base model. These improvements were mainly due to reduced radiative load and effective shading, not merely lower air temperature.

Overall, the effectiveness of pocket parks in improving thermal comfort in school open spaces depends on proper climate-adapted design, density, and quality of vegetation. Simply adding green space without an effective structure plays a limited role in reducing heat stress. The results of this study can serve as a scientific basis for developing design strategies for school open spaces in warm climates, aiming to improve student health and comfort.