Portable Infrared Sauna question

Hi,

I have had a portable infrared sauna since Nov 06, however i have read a couple of times that the air in Far Infrared Sauna s does not get hot, however the one i have does get hot. It was quite a cheap one, i am concerned it is not a genuine infrared sauna due to this.

It has this plastic mat thing you put your feet on that appears to get hot after a while. The sauna obsiously works in that it makes me sweat but maybe they just stuck a heater in there or something, and it does not have the same effect as far-infrared technology

Thanks for any guidance