I worked at a place (early '90s) where the server room was full of (some sort of) Sun machines and a legacy Symbolics Lisp machine. One day the server room's aircon failed and the Sun machines started to die for no obvious reason. The Symbolics was the only thing with a thermometer and its console error messages (complaining about the heat) were the clue that revealed what was going on.
Although it was the size of a fridge itself.