I don't know where in the middle east you lived or if you miscalculated how hot 120F is (it's almost 50c). I'm sure it gets that hot in the middle of the desert but most people in the middle east don't live in the middle of the desert.

I grew up in Israel and 40c (104F) was an unusually hot summer day (you'd get a few days like that per summer, maybe more now due to climate change). More common summer highs were around 30-35c.

EDIT: I underestimated how much hotter the Arabian Peninsula is compared to the Levant - a quick look via google maps puts Doha at 39c right now (at 9am!), while Jerusalem, Damascus & Cairo are at 22c, 24c and 27c respectively!

Kuwait. It is regularly above 45C in the summer. We would wear a hat and long sleeves and play soccer from around noon to 6pm during the hottest part of the day during summer break. Just have to make sure you have water. We also drank copious amounts of minty Laban (yogurt water with mint basically). To be honest I love the heat, all the sweat makes me feel alive.

I wish I could love it, I hate being sweaty (the climate is part of the reason I moved to Europe)!

I don't know exactly where you grew up, but if you factor in humidity the temperature in Riyadh is substantially lower than where I live in Texas. Numerically it's higher, but the low humidity makes it possible to sweat.

Slab City isn't that humid.

I think the emphasis was on being prepared.

If you grow up in the area surrounded by people who know the area, you'll do fine.

If you're casually wandering into an area like that coming from San Francisco or London expecting a fun weekend, you may very well pass out or worse.

And a lot of people die due to heat in the Middle East, and now in Europe in the recent heat waves. Of course it won't kill every single person but it's still a big threat to the unprepared.