I like to follow CASA’s recommendations on what to wear at https://www.casa.gov.au/standard-page/what-wear
“In the improbable event of an emergency, the clothes you are wearing can play a significant role in your safety. People wear synthetic blend fabrics …. However, they ignite quickly, shrink, melt, and continue burning after the heat source is removed.
Wearing clothes made of natural fibres such as cotton, wool, denim and leather offer the best protection during an evacuation or fire.
Avoid leaving large areas of the body uncovered. …. Wear non-restrictive clothing as this allows you greater movement.
The most common injuries to feet during accidents or emergencies can be prevented by wearing suitable footwear. Wearing fully enclosed leather low-heeled laced or buckled shoes, boots or tennis shoes is recommended.
So, the standard issue pilot shirt and trousers with synthetic underwear is not good for one’s survival in an accident where a fire is likely to occur (I know, it always happens to some-one else).
I sometimes use Nomex gloves too – apart from the safety considerations it overcomes those unpleasant, sweaty hands on slippery control sticks.
Plus: there are times when extras such as a Nomex flying suit, crash helmet and/or parachute should be considered.