Tons of people have wrapped their handguards in paracord, one of the first was "Bishop" who had a gem of a little Shortbarreled AR15 and if any AR is gonna get hot/toast with volume fire it was that thing. Short little 7 inch barrel or some rediculous thing along with an aluminum handguard, doesn't make for much of a heat sink to soak up the heat. Never heard of him complaining about melting the paracord.
Then from there it expanded, I saw his rifle and instantly knew that's what my accurized AR15 called for to help insulate the handguards that SPONGED up the heat from the 100+ degree summer's sun or got VERY cold during the winter. The way I wrapped my handguards I also managed to get additional functionality out of the pattern I used.
Directions that I gave many moons ago can be found here....
[url]http://groups.msn.com/TheMarylandAR15ShootersSite/wrapyourhandguardswithparacord.msnw[/url]
Other pictures of the beast rifle with the paracord wrap.
[url]http://home.bak.rr.com/varmintcong/jpar/jpar.html[/url]