This is an advantage for the remaining citizens and the heat-resistant tourists. You can walk now with less risk to collide with another pedestrian, which happens in other seasons very often. And the lines waiting at popular restaurants and bars are much shorter now.
The city also got more sex appeal. Many girls on the streets or in the restaurants & bars are very summerly dressed - one of the joys of a hot summer day.
Some of the remaining citizens escape to one of the plentyful parks of the city, sitting in the shade or are refreshing at the fountains. Others use the hot weather and play rock music on streets and open places. Maybe escaping is a mistake. In my eyes New York City is more attractive now. Enjoy!