I was born and raised in the Central Valley of California and used to laugh out loud when folks in the mid west, northeast and south would complain about temperatures nearing 100deg. We get at least 25 days a year of such temperatures.
Then I got sent on a job to Columbus Mississippi in August one year. It was 101deg and 92% humidity. It almost looked foggy the air was so thick. Only cooled to about 85deg in the AM.
I didn't know it was possible for humans to live in such conditions. It totally shut me down. Incapacitated. Hard to breathe.
Phoenix at 118deg is not THAT hot.
I live in eastern North Carolina. This morning it was 84° before 8 AM. The humidity in the evenings has been upwards of 70% and it’s been brutal.
It isn’t as bad as 92%, but you still almost feel like you’re walking in a steam bath. I grew up around here and the extreme humidity really bothered my asthma when I was a kid. Luckily I have mostly outgrown that.