Philadelphia is among major U.S. cities seeing its neighborhoods’ temperatures heat up to uncomfortable levels due in part to their surface materials. In response, the Philadelphia Office of Sustainability is testing a reflective pavement in one of its more prominent city parks. Kamil Kaloush, a professor in the School of Sustainable Engineering and the Built Environment, part of the Fulton Schools, explains how roads, parking lots and other large paved surfaces absorb daytime heat and reemit it into the atmosphere at night. Kaloush points to newly developed “cool pavements” that reflect the sun’s energy rather than absorb it. Philadelphia leaders see it as a promising defense against rising heat.