During extreme heat events, nighttime temperatures in the region's big cities are generally
several degrees higher28 than surrounding regions, leading to increased heat - related death among those less able to recover from the heat of the day.36 Since the hottest days in the Northeast are often associated with high concentrations of ground - level ozone and other pollutants, 37 the combination of heat stress and poor air quality can pose a major health risk to vulnerable groups: young children, the elderly, and those with pre-existing health conditions including asthma.29
Vulnerability is further increased as
key infrastructure, including electricity for potentially life - saving air conditioning, is more likely to fail precisely when it is most needed — when demand exceeds available supply.