Can't tell you about pants, but...

wool.

I had a full day of air travel recently in summer conditions wearing a light wool t-shirt and some top over it (can't remember exactly what). It was fabulous. I wore that t-shirt for nearly 24 hours in a row, running around in some city's transit system, sitting, flying, walking around really fast, getting out of the airport to drive to my parents' place in summery temperature, driving back to the airport to catch another flight, sitting again on another plane... and when I took the t-shirt off at home, it didn't smell anything. I was never hot nor cold. Wool is a wonderful temperature regulator.