Not that these don't melt; they're mostly fiberglass and polyurethane.
edit: It seems it doesn't melt even then.
https://m.reddit.com/r/askscience/comments/1rwxne/could_i_me...
That sounds like as close as we'll get to melting the stuff.
http://www.ncbi.nlm.nih.gov/pubmed/17907779
Not that these don't melt; they're mostly fiberglass and polyurethane.