Now placed hab mal ne ceiling between PVC floor and warmer and lo and behold, the rags as insulation to the ground enough that you finally feel the heat. Say lukewarm. You must in no way expect that the feet are properly warmed up. This part reaches to the maximum level, body temperature perhaps, nothing more. It warms all more than the soles of the feet, the heat does not rise to his feet. This is rather the temperature that I expect them to adjust by itself, if you wrap your feet in a blanket.
Conclusion: rather disappointing. 10 ° C and more the part would make sense.