About the MediCrystal® Mat Heating System

Sometimes it looks like the mat is not heating well and it is very important to understand whether it is heating normally or not. 

It is especially important for the larger size, full body mats which may be very powerful.

The main rule is that if the controller is on the maximum temperature level for one hour and the mat is covered with a thick blanket, human body or a pillow, the temperature of the bare mat surface measured immediately after you stand up or remove the pillow should be close to that shown on the controller.


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

Most of the time it is not same kind of heat, it is more “warm to the touch”. Most of the heating energy is transferred out of the mat as radiant infrared rays emitted by hot crystals, not by conduction or convection as with standard heating devices (which are hotter to the touch but do not penetrate to heat the inner body tissues nearly as much).

All MediCrystal® mats have an adjustable heat range of from 86° to 158˚F (shown as 30-70˚C on the controller). 

The temperature displayed on the controller screen shows the condition of the inner heating elements measured by sensors inside the different layers, including the heating system, with a variation of up to 5-10˚C (10-15˚F). 

The displayed temperature does not reflect the surface temperature, which may be significantly lower if the mat is not covered with a thick blanket, as the stones do not retain heat (the way metal does, for example). But in ideal conditions (when a blanket or a body is on the mat), the displayed temperature is only a little (up to 5˚C or 10˚F) higher than that of the bare mat surface.

If the mat is left uncovered, it should be slightly warm to the touch on lower levels, warm on medium levels, and very warm on high levels — but the amount of actually transferred heating energy is much higher than can be imagined. This warmth is deeply penetrating and very impactful. 

Our body does not have temperature sensors to detect radiant heat. So the mat should be set to a much lower, more prudent temperature than a standard electric heating pad. It demands extra care, especially for all-night use or extended-length procedures on the larger mats. 

The heat is activated when you lay on the mat and it penetrates into the body. 

It will only feel warm, even on the highest settings, and not too hot to the touch, even though the heat sensor might indicate a high temperature. 

This allows the FIR amethyst mats to generate the deep penetrating healing heat, without burning the body as conventional electric heating pads might (low temperature burns are still possible and so extra care is necessary)


Usually if the ambient temperature is around 70˚F, it should take less than an hour (30-40 minutes) for the amethyst mat covered with a blanket and thick padded protector to reach the maximum level of heating 158˚F (70˚C on the controller), unless it is too cold or the air flow in the room is strong enough to cool the mat down significantly. 

To accelerate pre-heating, please always put the included 3-D Protector Pad or multilayer waterproof cover on the mat and cover it additionally with a blanket.  During this time the gems become very warm and they start to emit warmth in the form of FIR rays themselves. 

The heating element’s temperature will be 150-160˚F inside the mat and the surface temperature of the mat (under the 3-D Protector pad, cover or blanket) is usually around 120-140˚F on the highest level, because when preheated the amethyst crystals transfer the most of the heat energy in the form of far infrared rays (FIR). All the above mentioned covers are at least partially permeable to infrared rays. 

Sometimes when the ambient temperature is low and it is windy, the mat can be only 100-110˚F on the surface, even when set to the maximum level, as the heat dissipates — but the mat will still generate the FIR rays. This penetrating heat is radiated in the same way as the sun’s energy, by rays, with only a small part through conduction (conduction or convection is the main method of heat transfer by conventional heating devices), and if you lay on the mat, your body will act as an insulator and absorber of the rays and this energy. 

If you measure the temperature on top of the protector (not on the bare mat), it will be even lower. But it shows that the FIR rays go through the protector well.

So if you turn the mat ON to heat up without the blanket and thick protector, and after 30-60 minutes measure the temperature of the surface of the uncovered bare mat, it may be only 100-120˚F (40-50˚C) even on the maximum (70˚C) level. 

But if you cover the mat with a thick blanket or lay on it, the bare mat surface temperature will go up to 130-150˚F (55-65˚C) under the blanket/body in 20-30 minutes. If you stand up and measure it again immediately, it will be just as high — but again, in 2 minutes, it will drop 10-15˚C because the heat will disperse and the stones will cool down quickly.


It is really a great advantage of the hot stone mats that the crystals can radiate healing, penetrating warmth and remain not so hot to the touch.

The heating area of the mat does not include the logo area. Only that part of the mat which is covered with tubes filled with amethysts (or other crystals) is heated. 

Most of the heating surface of the mat should be warmed uniformly. Only the highest and lowest tubes with crystals and mat side edges are not heated directly. Due to safety limitations, the heating elements are positioned approximately 1 inch from the edges of the mats, so the stones closer to the edges are heated indirectly by the other stones. It is normal for them to be cooler in the beginning but if you heat the mat for hours the edge stones will reach the same heat level.

So when the mat is preheated correctly (covered with a blanket and thick padded protector), most of the crystals’ heating area should be approximately the same temperature, +/- 10˚F.

To check if the mat is working optimally, cover the preheated mat with a thick blanket for 30 minutes and then remove the blanket and measure the bare mat temperature immediately. Compare the higher 1/3 of the mat and the middle part and lower 1/3 of the mat (not including edge tubes and crystals and crystals in the PU-film window). If the difference is within 10-20˚F, it is OK. 

The temperature may be significantly higher on the PU film window showing crystals and it will drop everywhere in minutes or go up if you cover the mat again or lay on it.

The temperature fluctuates very quickly due to the crystals’ ability to radiate heat. This is normal.


There is one more way to test the heating elements’ speed and power. It is not recommended to do frequently, as it can overload the heating elements and overheat the sensors. Also, the controller may stop heating if it receives different information about the mat temperature from different zones and layers of the mat.

“PILLOW EXPERIMENT” 

  1. Put a 3-D Protector pad from your mat set and a blanket on the mat and turn it on the highest level to preheat for an hour.  
  1. Remove the pad and the blanket from the mat and put a thick non-permeable pillow (like our MediCrystal® amethyst Pillow, or any other thick foam pillow) on the mat to block FIR heat and leave it for half an hour.
  1. Take away the pillow andimmediately measure the temperature of the mat surface under the pillow, and then the temperature of the surrounding area. We usually recommend using the standard Infrared Remote Thermometer. The temperature of the bare mat surface under the Pillow can be really hot and reach 140-160˚F (60-70˚C) under the pillow, but it may be only 100-120˚F (40-50C˚) on uncovered areas.

When we test the mats in the factory lab we have multiple temperature sensors attached to the mat at several points, and measure the temperature during 2 hours of pre-heating. All results are fed into a software testing program. The results are the same for the different models, though the heating speed may be vary slightly.

Really, all our mats are very powerful. There is an understandable seeming discrepancy between reading 70˚C on the controller and the surface feeling warm instead of hot to the touch. It may make some customers think the mats are underpowered, simply because we we’ve grown used to the way the hot surface of a conductive heating device feels. 

When customers start using the mat on only the highest levels, sometimes in several weeks we receive some totally opposite claims, that the mats heat too much — and we recommend setting it to a lower temperature. Customers then appreciate the controller’s ability to adjust temperature, and that the mat should be used on different heat levels for different conditions.

In a normal state, when the mat is not covered, it will never be hot on the surface. But it is important to remember that the FIR amethyst mats radiate deep penetrating heat into the body, and that the mat should be used on a much lower temperature than a standard electric heating device and that it demands extra care, especially for all night use. It refers mainly to larger sized mats, which are very powerful and may cause overstimulation, hyperthermia or a lightheaded effect if overused. 


Our skin temperature sensors are not familiar with radiant heat, so extra care should be taken even if you feel that the mat is not hot. 

It is amazing to lay on the warm mat and start to sweat after half an hour as if you are in sauna. Of course not everybody starts to sweat from the 1st use of the mat, as usually it demands some accommodation period for the body, but it eventually works, especially if you use the whole body mat.

If you need full energy, please, remove the thick 3-D air layer padded protector or Air Mesh Pad and use only the thin cover or simply lay on the bare mat. The mat has a built-in waterproof protective layer under the crystals and there is no danger of electrical system damage or shock from normal perspiration — but maximum sweat rates of an adult person can be up to 3-4 liters per hour, so we recommend protecting the mat with at least an additional waterproof cover so that all risk is minimized and the mat’s life extended. Crystals rays penetrate deep tissue and so sweating on the MediCrystal® mat is quite different than on a standard exercise mat. Sweat contains toxins released into the bloodstream from fat and other tissue and is sometimes very erosive. It can damage the mat’s upper layer or make it look bad or salted. 

The thick protector and/or 3-D Pad dissipate around 20-30% of heat. They are usually used for sleeping or long therapeutic procedures on much lower heat than the maximum. The main purpose of these thick pads is to avoid feeling the stones’ pressure during sleep or during long low-intensive procedures for people with lower body mass. 

Such cushioning pads are very useful during the first session when your body has not yet gotten used to the crystals’ pressure. But additionally, they protect the mat from sweat damage by evaporating (3-D) or absorbing it (fitted protectors).


In addition to toxins and heavy metals exuded with sweat, some useful salts and minerals such as sodium, calcium, potassium, and magnesium escape our bodies as well. It is very important to properly rehydrate, replenish electrolytes and minerals and take care not to overheat. 

A lot of mineral water, fresh juice or hot herbal tea before, during and after the procedure will increase sweating and make it safe. Soda or refreshing cold drinks do quite the opposite and decrease body core temperature and perspiration, and are not recommended.

There are more precautions with using the larger and more powerful whole body mat than with the Mini one, but the same precautions and general sense are important even with the Mini mat or Belt pad.

The big advantage of the Mini Mat is that you can use it to target a specific area of your body without causing full-body hyperthermia and sweating. 

You can also sweat and go through detox even with the Mini Mat, it just takes more time for each procedure than if you were to use the full body mat or a pair of mats. It is also quite normal to not sweat for a really long time, or not until after many procedures, if your body is heat resistant. Do not forget to cover your body with a blanket while you are on your mat to increase the effect. 

The Mini Mat is light and easy to carry or travel with and great for learning how in general hot stone mats work for you. Usually it is the first mat the customer purchases.

Sometimes for the most intensive procedures two mats are used, a person is “sandwiched” between them. The Mini mat works well on top, as it’s easy to avoid some oversensitive areas such as the genitals. Some men prefer two mini mats to one whole body mat so as to be able to have a gap between in the groin area.


Of course if you feel that a large part of the mat (1/3 not including the flat area without crystals) is really much colder than the other part, it may mean sensor is malfunctioning and needs replacement. 

Or if the temperature measured under a pillow or thick blanket shows 100-110˚F (40-45˚C), the same as on the bare surface of the mat, it means something is faulty.

Sometimes a controller fails and does not cool down the mat. No matter which temperature is set, it automatically heats up only to maximum level. In this case the controller would need to be replaced.

MediCrystal® Classic mats are covered with a 2-year warranty, and usually we resolve such issues very quickly and for free. But fortunately, most errors can be resolved if the user simply reloads the system.


The most frequent reason for the new controller fault is an incorrect order of controller connection.

You must first connect the mat to the controller, and only after this plug the controller into an electrical outlet and turn the controller ON. 

When you disconnect, first turn it OFF, then disconnect the plug from the socket, and only after this unplug the controller from the mat. 

If you connect the controller to the power source first, the safety program will lock it and go into safe mode. It may start to beep or will show OF or OP error on the screen.

To reset it just reconnect it in the correct order.

Some controllers with temperature dials need you to rotate the dial to minimum position before turning them OFF. Otherwise the next time you turn the controller ON it will not start work until you rotate the temperature dial back to the lowest position.

Please activate the timer button and choose one of the timer settings for the mat to start heating. Some models of the controllers do not activate the heating function unless a timer is set.

Please check that connections are tight. 

A loose connection can cause loss of signal exchange between the mat and the controller, and when too many errors accumulate the controller’s calibration may fail.

Reconnection and reset are the most common ways to eliminate errors and reload the controller.

Sometimes the easiest way to solve the problem is to disconnect the plug from the socket first and then from the mat connection terminal. 

When you disconnect the plug from the mat, please always do it carefully with two hands, holding the connector with one hand while the other hand pulls the plug. Pull the plug out of the connector on the mat carefully as well. 

After this always first reconnect the controller to the mat tightly and then plug it into an electrical outlet again. 

Do not pull it by the cable or the connection between the mat terminal and the controller plug may become loose and it will cause errors and signal loss.

But if reconnection or any other way of troubleshooting do not improve the situation, it likely means that there is a problem with the controller. 

If controller is dead, or shows persistent errors even after reconnection and troubleshooting, it is a problem with the controller and it may need to be replaced. In such cases we usually expedite a new controller.

If the controller is OK, shows the current ambient temperature but the mat does not heat up to the set level even when the time is set, it is the mat’s inner sensors causing the problem, in which case the whole unit may need replacement. In such a case we would usually expedite a complete mat set to customer.

We don’t expect either of these to happen with your mat. But if your experiment with the pillow on the mat shows that it does not heat well, we will resolve it ASAP by either replacing the controller or the whole unit

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