Humidity. Humidity is the difference. The more humid the air is, the more oppressive will the heat feel. From experience, it becomes more and more of a bitch the more you go towards south in europe.
When the sun sets in a desert town, the temperature drops from oppressive 45 °C to tolerable 35 °C. That’s when people take their children to the park, people go shopping etc. The whole town comes to life when it’s only 35 °C. That sort of dry heat is so much more pleasant than humid jungle heat.
From travelling through the UK in a former heatwave, my main takeaway was that buildings and infrastructure are not built for the heat. Not even talking about AC, just the passive features of buildings in the UK are about keeping the heat in, understandable given the historic climate, but hard to overhaul.