BackgroundThe urban heat island (UHI) significantly affects the health of people living under its influence. Urban children are highly exposed to environmental exposures that can affect the occurrence of atopic diseases. This study aimed to determine the link between air pollution, the UHI phenomenon, and allergic diseases in preschoolers.MethodsThe study group included 310 5-year-old children attending kindergartens in the urban and rural areas. Each child had skin prick testing (SPT), the measurement of volatile organic compounds (VOCs) in EB, and measurement of particulate matter (PM2.5 and PM10) using the personal aspirators. The children’s health questionnaire covered the following symptoms: asthma, food allergy, allergic rhinitis (AR), and atopic dermatitis (AD). The analysis of the UHI phenomenon was based on data from the Weather Research and Forecasting (WRF) model for the years 2014–2019. Air quality analysis (PM10 and PM2.5) was performed for the years 2015–2019 using the CALMET/CALPUFF modeling system.ResultsThe place of residence of 165 assessed children was localized in a rural area, whereas 145 children were lived in an urban area. A total of 44 children lived in the UHI zone: 71.8% of them lived in tenement houses with traces of moisture and mold at home (35.9 and 33.3%, respectively), and 69.2% of them were exposed to tobacco smoke. Children from the UHI often significantly suffered from atopic dermatitis (25.6%) and allergic rhinitis (28.2%). The highest concentration of PM2.5 and PM10 was confirmed in children living in the UHI. There was a clear trend in the VOC profile between the three categories of place of residence (rural area, urban area, and urban heat island).ConclusionWe demonstrated that living in the UHI zone independently increased the risk of developing atopic dermatitis and allergic rhinitis in our cohort.