At my flight school we were given a new uniform, 100 % polyester. I refused to wear it, claiming it's highly flammable. Incidentally, the new cheap trousers totally lacked shape and style and I could legitimately use my old, less flammable, smart looking trousers
On the other hand, I am quite liberal when it comes to clothing. Yes I admit, when I fly privately I use shorts, T-shirt, maybe even sandals at times. But considering the temperature in southern California it would be totally unrealistic to force myself and my passengers to wear overalls when temperature reaches 50 deg C inside the aircraft. What is a greater threat??