Policy-relevant indicators for mapping the vulnerability of urban populations to extreme heat events: A case study of Philadelphia March 04, 2015 Weber, S., N. Sadoff, E. Zell, A. de Sherbinin. 2015. Policy-relevant indicators for mapping the vulnerability of urban populations to extreme heat events: A case study of Philadelphia. Applied Geography 63:231–243. http://dx.doi.org/10.1016/j.apgeog.2015.07.006.