The Quantum Pad makes the Biomat more comfortable and I only use it when sleeping on it since I am not concerned about getting a high conduction heat. The pad blocks nearly all the direct heat. You still feel the warmth but its not skin on skin contact with the amethyst. Since it doesn't block the far infrared rays, it is ok to sleep on it but to raise the core body temperature 3 degrees is nearly impossible. Maybe if its summer time and the room is 100 degrees and someone loaded up on too much niacin.
Note: the ribs of amethyst stones in the Biomat can uncomfortable for many beginners. As people gain more positional tolerance people should be able to use their Biomat without any cushion at all.
People will still sweat on the Quantum pad since most people have to turn the setting up 2 to 3 settings higher to feel the same heat. But, it still will never get to 158 degrees.
Sleeping on the Biomat
Warnining - do not put normal blankets or any type of fabric or towels to cushion your Biomat if you don't have the quantum pad if using it on high temperature settings.
The Quantum pad is guaranteed to not block far infrared and allows heat to escape through. If the heat is not allowed to escape by using cushions that don't allow heat to escape it can overheat the heating elements under the amethyst.
Older version of the Quantum Pad - Make sure you get the latest and most updated version of the Quantum pad - Purple is the newest version and the manufacturer does not ship the older color Quantum pad. This picture is what the older Quantum pad looks like.
...because no one gave me advice after I bought my first Biomat