On the topic of ironing and its reduction of Nomex's fire-retardant qualities: I think that's a myth. I did some searching on the DuPont site and on a few sites of companies that market Nomex clothing for other uses, and it seems that the fire-retardant quality is inherent to the material. The fabric doesn't have a coating that can be compromised from iron at the "synthetics" setting. The only thing that ironing or using too high a dryer setting can do is to make it wear out more quickly. If you crank up the iron to super-duper hot, and let it sit there for a minute, then you might run in to problems. But I'm not going to test it. I'm a newbie/wannabe with newbie stuff.
"Of course this is a thread, by my name's not Jack - it's Greg."