How does the GoSun remain cool to touch while cooking?

We often refer to the "magic" of our vacuum tubes, but make no mistake, it is pure and simple science! Between the vacuum tube's two layers of glass is a layer of... nothing! That's right, nearly all of the air has been removed, preventing any convection or radiation of the heat from one layer to the other. Without a thermal bridge to move the heat, the tubes external face remains cool while the internal tube can hit temperatures in excess of 550°F/280°C

Pretty cool right?!