In my early mil flying career I wore Nomex gloves as part of my fashionable Nomex flight suit ensemble because it was required. However, one day I ended up flying with an old aircraft commander who had been in an runway overrun accident some years before. Everyone had gotten out of the aircraft, but not until after a flash fire had erupted. This gentleman had been wearing his gloves, but because the day was hot and humid, had rolled his flight suit sleeves up a couple of turns during preflight. He had perfect burn scars all the way round his arms in that area above the point where the glove ended and below where his rolled-up sleeve began. Burns to that bit of exposed skin on each arm was the only damage he had suffered.
From that day forward I wore them because I thought it was a good idea, not because they were required. True, when it’s 1000 degrees outside of the flight suit it is pretty much a safe bet that it’s 1000 degrees inside the flight suit. In such cases of prolonged exposure to heat Nomex isn’t going to save you. However, there ARE occasions where Nomex CAN help, and like everything else related to aviation safety, you hedge your bets when you can. To this end, when I fly as a passenger even today I opt for new jeans and a cotton shirt because I believe that in a fire they just might give me a second or two that I wouldn't otherwise have. I'll take those seconds anywhere I can get them. In a case like this where there's little downside to dressing in this manner, the cost/benefit analysis seems to favor natural fibers over stuff that'll melt to your skin at the first sign of danger...
The point about rings is also well-taken. I had a healthy respect for the ring rule and never wore any around the aircraft. However, I am convinced that having my gloves on and tucked into the sleeves of my flight suit saved me being strung up by my watch band on more than one occasion.
Dave