Yesterday it was sunshine but -7C/19F and a little bit windy. I took a walk along the coast and it was cold, especially on my hands, even if I had gloves on them (quite unusual for me). I also felt a little bit cold around my legs but not that much.

In the afternoon I went out again with one exception, I was in trousers. They were warmer around my legs, but on my upper body I felt really cold and not well.

My conclusion: By wearing a kilt your legs are slightly colder compared to trousers but the overall balance is much better with a kilt.
That is to my opinion also the case when you are in door. Wearing a kilt you can do with a lower temperature by the same comfort level. Kilts might be advisable for reducing CO2?

Greg