This is mostly cultural.

US based flyers (and hence US carriers) are accustomed to full air conditioning all summer long -- much of the country (exceptions are Alaska, the PNW, and northern New England) is mechanically cooled in the summer months. This also means the air is dryer -- air conditioned cooling also means dehumidification.

In Europe, air conditioning is less common. When I lived in Germany, the FSU, and other parts of northern Europe, I noticed that people kept rooms much warmer than I was accustomed to (21C is fairly standard in the US, Europe often sets the temp somewhere around 23 or 24). People also wear lighter, more breathable clothing nowadays, making them colder and requiring more room heat.

The few places where workers still wear wool suits every day (banks, mostly) will often be kept much cooler than other office environments.