###### Abstract  
This systematic review analyzes comprehensive indoor environmental quality (IEQ) field measurements in school classrooms from 2020 to 2024, focusing on the post-COVID-19 period. Following PRISMA guidelines, 70 studies were selected from an initial pool of 251 articles. The review examines thermal comfort, indoor air quality, acoustics, and lighting parameters, identifying measurement methodologies, correlations between parameters, and post-COVID-19 adaptations. Results indicate significant modifications in ventilation strategies and IEQ monitoring approaches, with an enhanced focus on air quality parameters. The findings provide evidence-based recommendations for IEQ monitoring and optimization in educational environments. Keywords:indoor environmental quality; school buildings; field measurements; post-COVID-19; systematic review +
Footnote †: journal:  
* Consideration of parameter interactions. * The implementation of comprehensive assessment protocols. Recent studies have highlighted the complex relationships between various IEQ parameters and their combined impact on student health, comfort, and academic performance. For instance, increased ventilation rates, while beneficial for air quality, can affect thermal comfort and acoustic conditions, necessitating a balanced approach to IEQ management. The comparison of indoor environmental conditions and energy consumption before and after the spread of COVID-19 in schools in a Japanese cold-climate region revealed how ventilation changes, although essential for mitigating viral transmission, can influence both thermal comfort and energy use in classrooms [5]. Similarly, a case study in a Spanish region with a Mediterranean climate highlighted how ventilation conditions, while crucial for air quality, can also affect thermal comfort in examination classrooms during the COVID-19 pandemic, indicating that excessive ventilation could make it harder to maintain comfortable thermal conditions [6]. For instance, the analysis of heat use profiles in Norwegian educational institutions during the COVID-19 lockdown demonstrated that despite a significant reduction in occupancy, heating systems continued to operate at the same level, which raised concerns about energy efficiency during the pandemic period. The study further suggested that reducing heating to the level of night-time use could save significant energy, offering valuable insights into energy-saving strategies during periods of reduced occupancy in educational institutions [7]. Similarly, a study by [PERSON] et al. [8] on surface passenger mobility and related CO2 emission changes in Europe revealed that COVID-19 lockdowns significantly altered transportation patterns, leading to a sharp decline in emissions. This shift in mobility patterns may offer insights into broader strategies for reducing emissions in public spaces like schools, where managing airflow and reducing energy consumption are key objectives. Additionally, the ventilation conditions in schools during the pandemic were shown to influence thermal comfort, with excessive ventilation leading to discomfort in certain climatic conditions [8]. Based on these studies, it is evident that thermal comfort and indoor environmental quality are critical factors for the well-being and cognitive performance of occupants in school buildings. In particular, recent studies, such as that conducted by [PERSON] et al. [9], have highlighted the importance of optimizing energy efficiency in school buildings, especially concerning lighting and cooling conditions. These findings are essential in hot and arid climates, such as that of Saudi Arabia, where thermal comfort can be a challenge due to high summer temperatures. Other studies, such as that by [PERSON] et al. [10], suggest the importance of establishing health-based criteria to prevent overheating in schools, as prolonged exposure to high temperatures can impair learning capacity, particularly among younger students.