Ok, so it doesn’t mention wet bulb temperature anywhere, so I went to figure it out. The first thing I was surprised with is apparently most of online calculators don’t take in values higher than 50C.
I couldn’t find the exact data about humidity for that day, but it has been 35-40%+ at a minimum for most days in that region, sometimes even reaching 90%.
So, 52C at around 40% humidity is 37.5C in wet bulb temp. The point of survivability is around 35, and most humans should be able to withstand 37.5 for several hours, but it’s much worse for sick or elderly. 39 is often a death sentence even for healthy humans after just two hours — your body can no longer lose heat and you bake from the inside. That’s like having an unstoppable runaway fever. And with that humidity it’s reached at 54C.