I would love to see another player with a 'glow' walk into town and all the guards and PCs open fire on him/her. We wouldn't want any of our nice shiny towns infected with radiation poisoning would we!? This gives me an idea for a great quest...
Get radiated or pack a bottle of radiated water to throw on some jerk or jerks. Get out of dodge.
What he meant with the glow was a place in fallout 1, which had major radiation levels, a quest from BoS led you there, to pick up a data file and then return it, after that you would be able to join the BoS. Problem was that you couldn't get close (even on worldmap) without getting severe radiation poisoning, you had to bring lots of Rad Away and Rad-X, rad-x to lower radiation intake and rad away to get the poiso out of your body
I'm guessing you are referring to fallout threes "glowing ones". Fallout 1,2 glowing ones where still a bit human-like (they didn't go rampage whenever they saw you and they didn't shoot our radiation with a big boom)