I've made tons of potholders, and use a layer of Insulbrite with a layer of 100% cotton batting (it's less flammable than the cotton/poly blend), and have never had a problem getting burned. Even grabbing my turkey roasting pan that's been in the oven for hours, I've never had a problem with heat getting through. I don't quilt them very densely, allowing them to be a bit poofier : )