I recently read an article about at what temperature/humidity can a human not survive. Their answer was at 95 degrees with 100% humidity a human will die in 6 or 7 hours, no running required. In 100% humidity the body still sweats, but there is no evaporative cooling. The 95 degree air is hot enough that it isn't contributing to body cooling either. As time passes, internal temps rise and eventually organs begin to succumb to it and shut down.
The point of the above should be to keep in mind that really high humidity with high temperatures impairs your body's ability to cool itself.
From an article I just read:
"Some of the most important organs affected by extreme heat are the kidneys, heart, gut and brain.
When the body is dehydrated, the brain sends a signal to stop circulating as much blood to the kidneys to avoid losing fluid in the form of urine. The kidneys quickly become deprived of oxygen, which damages cells there and can cause kidney failure.
When the heart, which is working in overdrive, can’t keep up with the demand of increased circulation, it also doesn’t receive enough blood and becomes deprived of oxygen. This can cause potentially deadly damage. It’s especially a concern for people with underlying conditions that weaken the heart muscle.
Cells in the gut appear to be particularly susceptible to heat. When they become too hot, the wall of the intestines can start to break down, allowing bacteria to leak into the bloodstream."
I had heat exhaustion a few years ago, and it wasn't fun. Felt like 4 days of the flu. My wife had heat exhaustion on Thursday, and she's finally over it today, 4 days later. We have had heat indexes over 100 by 10:00, then topping off around 108.
I stopped golfing last week. When the feels like temperatures get over 100, it's not only less enjoyable, it's just dangerous, especially at our age. Some of my fellow golfers chide me for not being manly, but I prefer to focus on indoor activities when it gets crazy hot. I have been doing genealogy and planning some travel - especially to cooler areas