I live in Kentucky and I just checked some of the records from our Mesonet site. Last July we did have several days where the temperature and relative humidity were over 90. It's not just in the Persian Gulf or New York.
Bob, you evidently have never spent a summer in New York.
In the United States, there have never been "90 degree temperatures with 90% relative humidity." In fact, only Persian Gulf areas approach this. If this is the level of expertise in this book, then the book is worthless, from a meteorological standpoint.