This study examines urban heat islands in Vila Velha, Brazil using Landsat 5 Thematic Mapper imagery from 2008-2011. The methodology uses a mono-window algorithm to calculate land surface temperature and determine its spatial and temporal distribution. Results show higher temperatures in densely urbanized areas of the city, with extreme heat occurring in different seasons annually. A correlation analysis finds higher temperatures correlated with increased built surfaces and lower temperatures correlated with vegetation. An urban thermal field variance index is used to assess ecological impacts, finding urban areas indicate worse conditions while green spaces show excellent conditions. The methods aim to better distribute urban and green spaces to mitigate urban heat island effects.