I too think they may be referring to the space blanket stuff that is for retaining heat. I don't know how well that would work being punctured by the quilting. I think just donating the space blankets themselves would work better.
Saw a story on Good Morning America today about a young man trying to stay warm at a vent in Washington. Apparently, the White House photographer went out to snap a few pictures and this photo was featured in print. Someone on social media notified the parents and they were able to track him down.