Developed areas with a lot of paved surfaces, large buildings and traffic often experience higher temperatures than areas with more green space. These urban heat islands contribute to air quality issues, which can lead to an increase in asthma and other respiratory problems. The good news is that the solution to some of the effects of urban heat islands may be as close as the nearest tree, with temperatures in the shade 20 to 45 degrees cooler than peak temperatures in unshaded areas. Take a look at the temperature differences we found between shaded and unshaded areas around Texas.