It's documented in the book Google Plex. Google hired a neurosurgeon as their first infrastructure engineer. His fast task was to increase the rack density to s

It's documented in the book Google Plex. Google hired a neurosurgeon as their first infrastructure engineer. His fast task was to increase the rack density to save company money. The dude figure out how to pack 10x more processing power into the same size, resulting in overheating of the colo space (or overloading the power line? I can't remember exactly). The colo company had to tear down an entire wall and used a 18-wheeler modified mobile air conditioner. I probably got some details wrong as it's been years since I read the book, but you get the spirit.