37-40 C is hot, granted. But, isn't this the temperature that places like Bagdad, Northern India etc. endure every year for weeks?
Besides, Europe is not such a small place either. Many houses in the South are geared towards hotter weather and have the the features you described.
They also get notoriously cold in case there's a cold snap, since they aren't insulated very well.
And solar is kind of hard to put on walls of a building you do not own.
The people who live in these areas aren’t used to this kind of consistent extreme heat, especially considering how humid it will be.
Northern India is actually experiencing a heat wave too https://en.m.wikipedia.org/wiki/2019_Indian_heat_wave