Do you recommend to cover Ereada® mat surface when in use?

You can use an uncovered mat if you need extremely high intensive heat and hot stones.

But especially for your comfort and mat protection, we include Thick Padded Protector with an air mesh layer and/or Thin Protective Cover. Both are waterproof and sweat absorbing but well breathable and permeable for FIR rays, ions, PEMF.

NEVER cover the mat with anything but the covers provided with it or towels, sheets, and blankets made from natural materials (like cotton, bamboo). The material has to be permeable to FIR rays. If the material is not permeable (rubber), the FIR heat will be trapped, the mat could overheat and even burn. 

Some examples of not allowed objects on top of the mat can be - controllers, thick pillows, books, yoga, and camping mats.  

So, for your safety, please, never keep or put anything on the mat besides permeable covers. Only your body can be on the mat. 

If you do not have Ereada® Protectors, you can use a blanket or a towel. Natural materials as bamboo, cotton, or wool are preferable.

The main point of the cover is to protect your body from direct contact with hot stones and absorb your sweat to protect the pad.

It would help if you covered the mat completely while preheating it.

If you cover the mat partially, the temperature sensors positioned in the different layers of the mat around all the surfaces will report different and controversial measurements to the main controller.

Finally, the controller may lose calibration and start to work incorrectly or malfunction.

So, please, always cover the mat completely while it is preheating to set level.