Abstract
Urban areas typically get much hotter than rural or natural areas. The higher temperatures in cities are caused by the presence of lots of buildings and streets, which heat up in the sun because they are made of materials that can not hold much water. In hot urban areas, called urban heat islands, people and animals stay cool by sweating, panting, and staying in shady areas. Even urban trees can stay cool by transpiring, which is like sweating. In fact, trees transpire so much that they can cool down the air and reduce the urban heat effect—like natural air conditioning. Although the urban heat effect is typically viewed as a problem, scientists can study the plants and animals living in urban heat islands to understand the effects that rising temperatures due to climate change will have on these species in their natural habitats.