Heat Wave Grips the Northeast United States Nearly 60 million people are under a heat watch, warning or advisory from the National Weather Service. Nearly 100 million people will see temperatures climb above 95 degrees Fahrenheit this week. A majority reside in the eastern third of the nation. The heat wave began over the Rockies and Midwest late last week. Several high-temperature records have been recorded. In New York and New Jersey, high temperatures and humidity will combine to create a dangerous situation. According to the National Weather Service, heat illnesses are likely.