Reironisation of the universe after the 'big bang'

If we [ i ] take the 'observed' data from the below article.  The average background temperature of inter-galactic space [average 2k] of observed 1.6k [charge?] appearing at the centre of a galaxy - 

[emergent detection point, in amongst the below average background thermal energy of a {size ratios} galactic core]

- surrounded by a balance of the usual cluster of close orbiting stars, I presume that the quantum 'tunneled' emergent cold hydrogen is a snap shot [type] of a big 'bang' scene.

Cold update:
''Walked to the coast to take a picture. The cold zapped my iPhone battery from 100% to 3% in 5 minutes once I took it out of my pocket'' - Jason Burg


Resultant from the above article evidence,

Would it be unreasonable to assume that reironisation would require the warming of the electrons of the hydrogen [atomic ironisation] for their energy of potential to be invigorated?