I worked at a crappy call center in Tampa, FL (ca. 1998-99).... that alone should make you shudder. There were stacks of machines, both servers and desktops running server OSes, all stacked on top of each other (many turned sideways), much higher than my head. In fact, 2 stacks were higher than I can reach on my toes. these ran the whole infrastructure, all the PBX stuff as well as an expansive voice recording system (we were in the verification biz, so all call got recorded every day). The physical danger of these stacks was apparent, but they remained in that configuration until long after I left. How we made all that work was a mystery to me at the time (I was strictly break-fix and in house audio guru). Looking back, I'm not sure I would have wasted a match to burn that place to the ground.
(Side note on the miserliness of the owner - our data disposal routine was to microwave a stack of DVD-Rs every day. In the break room microwave that everyone used. Not sure how the EPA never got called... oh, wait... it was in Florida.)