As noted above, fire isn't the only concern we should have when it comes to garments.
Winter is just around the corner and for us northern climate kinda folks, that means we may need to change our basic "get up" so to speak to relate be appropriate for colder weather.
I always thought that the Department of Interior's policy on dress was pretty simple and easy to understand. To paraphrase, it required every occupant of an airplane, regardless of season, to be dressed appropriately for extended time on the ground over which the flight was to be conducted. Dress for conditions, assuming the worst could happen, in other words.
As noted above, cotton loses most of it's advantages in cool, cold or especially wet, conditions. Wool is the go to material for cool, damp conditions. Nowadays there are really nice Merino wool long underwear as well as wool outer wear, such as shirts, trousers, etc. And, I'm very impressed with the comfort of that stuff, at least compared to the wool long johns of decades past.
So, it's actually pretty easy to dress in mostly wool clothing in winter. The good news is that wool is also inherently slightly fire resistant. Department of Interior allowed substitution of wool for Nomex for low level ops in winter for that reason. But, there is also Nomex outerwear, including jackets, snow pants, parkas, gloves, etc.
In winter, your feet are really important, and you have to take care of them if you're out in the wilds. I generally wore Bata Bunny Boots in interior Alaska winters. They're about the only footwear that will keep your feet from freezing, even if your feet are wet. I've filled them with water after stepping in deep overflow, and simply removed the boot, dumped the water out, wrung out the sock (wool, of course) and put the boot back on.....at -30 F. And spent the rest of the day and half the evening getting unstuck. Try that with most other boots and see how it works. In particular, a lot of boots these days have some sort of nylon or synthetic material incorporated into the structure of the boot. Again, fire will melt that stuff, so try to stick with something all leather or rubber, like the Bunny Boots.
Gloves: In winter, I love the military style Nomex/leather gloves for a base layer. Then, if I'm going to be in and out of very cold stuff, a pair of heavy mittens hang on a lanyard around my neck. In milder weather, the Nomex gloves are enough for a lot of stuff.
Mainly, just give some thought to what you're wearing. As I noted in the first post of this thread, garments made from synthetic materials probably aren't appropriate for flying, regardless of weather. That said, there are some really good synthetic garments for winter survival......
MTV