Average HI temperature (left) and CO filling factor (right) as a function of the relative distance r_rel. Black solid line shows the average for the whole datacube, blue solid line shows the profile for one Galactic HI supershell, GS242-03+37. Dotted lines show the number of pixels, from which the average was calculated. Red lines with numbers give extents of different “types of environment”. Red arrows indicate the transition between bubbles and walls.