The heat index, which takes into account both temperature and humidity, reached alarming levels in several cities across the United States. In Chicago, Illinois, the heat index peaked at 118°F (48°C) on July 14, 1995, leading to over 700 heat-related deaths. Similarly, in New York City, the heat index reached 108°F (42°C) on July 22, 1995, resulting in over 300 heat-related fatalities.