A Comprehensive Investigation of Thermal Comfort and Heat Island Phenomena in High-Risk Regions of Putrajaya

Urban heat islands (UHIs) are localized areas within cities that exhibit significantly higher temperatures than surrounding rural regions, primarily because of anthropogenic activities and urban infrastructure. Understanding thermal comfort (TC) is essential, as it directly influences the well-being and quality of life of urban populations. This study investigates the presence of UHIs in Putrajaya and evaluates the TC levels experienced by its residents. TC is assessed using the Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices, following internationally recognized standards ISO 7730 and ASHRAE 55-1992. Field measurements were conducted with the EK-H4 data logger as well as Thermal Comfort Station (TCS), which records key environmental parameters including air temperature, mean radiant temperature, relative humidity, and air velocity. Data collected were retrieved using EK-H4 V1.0 software and analysed with Microsoft Excel. A psychrometric chart was employed to visualize environmental conditions and identify TC zones. The results indicate that PMV values ranged from -1.0 to +1.4, reflecting considerable variability in thermal conditions across different locations and times. Recorded air temperatures ranged from 28.4°C to 36.9°C, relative humidity varied between 48.1% and 72%, and air velocity ranged from 0 to 2.32 m/s. These findings confirm the presence of localized UHIs in Putrajaya and reveal varying levels of thermal discomfort, highlighting the need for urban planning interventions aimed at mitigating heat stress and enhancing urban liveability.