I live in London, and I was writing mostly about the fashion here. And the maximum it reaches in London is 30 degrees Celsius and has very low humidity. I'm pretty sure they are not getting more naked because of the humid heat.

But even in humid places, I believe a flowing linen dress won't stick to the body and will do a much better job in keeping us cool, as it permits movement of air from the skin through the fabric, allowing heat to dissipate and reducing humidity. It also absorbs moisture well, keeping the skin dry and increasing evaporation. Many cultures have traditions of flowing garments which allow air circulation close to the body. In addition to being cooling, this also helps to keep the body dry, preventing irritation, rashes and skin infections.