I use my Single Size amethyst tourmaline Mat and wake up several times each night with some kind of buzzed feeling. I used it on the 50°C setting, the mat was only slightly warm. Is this normal?

The FIR amethyst Mat does not work like a conventional heating pad. 

It is not the same kind of heat; it is more warm than hot to the touch. In the form of far infrared rays, most of the heat is transferred by radiation, not by conduction as with standard heating pads, which are hotter to the touch but far less effective at heating the body. 

The mat should be slightly warm on lower levels, warm on medium levels, and very warm on high levels, but the actual transferred heat energy is much higher. 

Our body’s temperature sensors do not feel the FIR heat in the same way as the conductive heat we feel when we touch a hot object. So the mat should be used at a much lower temperature than standard electric heating devices or pads.

Be extra prudent, especially with longer sessions or all-night use. If the level is too high, you may feel buzzed or overstimulated. 

Always go down and restart from a lower temperature level, shorter session, less frequent procedure.