a super shelter is a tarp shelter with a reflector inside, then you put plastic sheeting in front of the opening. with a fire in front, it gets really warm in the shelter. mors kochanski has covered it quite a bit, i think he coined the term.
last cold campout i did, i tried one. but it wasn't built well and i was too drunk to tend the fire at night, so i woke up freezing my ass off...