OK, so now we have concluded that sceptimatic does not believe that his theory can work. I explained how it would happen in his theory and he strictly dismissed it without explaining why.
As for the thermos keeping something hot for hours, yes it does. However, as explained earlier, they use reflective materials to reflect the IR waves back into the liquid.
I mean, the use of reflective materials is used frequently as insulation. Why is some insulation backed with a reflective material if all it is doing if going in a wall? It is to reflect incoming IR. Why do the EMT's wrap someone going into shock with a thin mylar blanket to help them maintain their temperature? It is to reflect the IR back to their body.
If you have something getting heated up solely by radiation, why would it not be able to cool down by radiation? If half of the material is in the sunlight, and half is in the shade, it would be radiating approximately the same amount as it is absorbing.
Not sure why this concept is so hard to get.