Mark, for the merit badge, you can't actually USE anything other than what's available in the area you'll be doing the camping. And the night of the overnighter, you pretty much get what you're wearing. So, yes, you can wear 5 or 6 layers, but you can't bring a space blanket or poncho or anything like that. You sure as heck can't use those things to construct your shelter.

At least, that's how mine was. I don't have the latest edition of the MB manual in front of us.