OK, I made a mistake. Nomex is sythetic. The difference is that it will not melt onto your skin.
But you won't catch me wearing nylon or other meltable materials, after I have seen what they have done to aircrew in the past.
If you have something better than cotton at your disposal, then by all means wear it, and tell us all how easy it is to buy.
But try to avoid wearing something worse - like Nylon....
I can't believe that pilot stores sell flying jackets made of this stuff !!