I'm not sure if you're replying to my post or comms, thseng.

In fairness to comms, as I re-read comms' post, I think I am not correctly reading the intent of his point about Nomex. I think we're both saying the same thing--the heat will get through the Nomex, and in that case, yes, it's probably better not to be wearing synthetics underneath. I was thinking that his phrase "doesn't stop" meant "does not insulate at all". That's why I was mentioning that Nomex does have insulating properties, more than your typical fabrics.

I was trying to look up the insulating property for Nomex and I happened to run across this statement which would seem to a supporting argument for the show's suggestion to wet down your clothes. From this page, in the Vertical Flame Test section.

Quote:
As you can see the polyester cotton blend and the 100% cotton test fabrics continued to burn until the whole sample piece was consumed. This test goes to show what a garment made of these non flame resistant materials will perform like when subject to a flame source. The continuation of a fabric to burn even after it has been removed from the flame source is the main reason that injury and/or fatal disasters can occur to a person wearing these garments. The Nomex on the other hand self extinguished within a 3.1 to a 3.3 inch burn length and had no after flame glow.


So, if we go back to that flashover scene from the episode. Remember that his clothes kept burning after the flashover (actually...was that before or after they wet themselves down???). If he could have avoided that additional heat from his clothes continuing to burn after the flashover, his injuries may have turned out less severe or burned less of his body.