The temperature fluctuates between 65 and 72 degrees C, is this normal?

It is normal for the temperature to fluctuate slightly once the mat reaches the set temperature. This happens because the mat heats up slightly above the set level and then stops heating. As the temperature drops a little, the heating resumes again to reach slightly above the set level. This cycle continues and is the normal operation of a thermostat-type device.

If the thermal insulation conditions of the mat change, the temperature may drop more noticeably. For example, if you stand up from the mat or remove the blanket and protector and leave the mat uncovered for several minutes, the temperature may drop by up to 20°C. This occurs because the heated crystals quickly radiate their stored heat into the surrounding air.

In such a case, the crystals may still feel warm to the touch, but even if the temperature indicator on the controller shows around 65°C again, the mat may feel only slightly warm unless it is covered again or someone lies on it.