Not meaning to be a stick in the mud about the practice of ki.
But the stuff shown on the listed site can be duplicated by anyone with a simple bio-feedback machine and some spare time.
Some things just can't be explained, this is not one of them.
If you want to see the run around ask them this---
If the the sensor was set to record any temp above 98.6--which they say it is--what is the temp recorded???
Could be 98.7 for all we know.
You can do simple (and small) ajustment to your body temp just by relaxing and taking some deep breaths--kinda fun to do with those simple liquid crystal (I think) "stress test" things--you know where the color is effected by your level of stress.
Actually it reacts to to the level of heat given off by your hand.
Also notice that the heat given off by the wrist STARTS OFF ALREADY hotter--mainly because the skin is very thin over the wrist, the veins are close to the surface, and they are a major "pulse point" as it were.