It is amazing we didn't burn the building down
Our previous office was on the top floor (servants' quarters) of a grade 2* listed 19th century manor house. Over the years our number of servers crept up from 2 under a desk in an office (one of the bedrooms) to a whole room. We had 2 aircon units in the room but they were a bit dodgy - at one point they failed over a weekend and when we got in it was subtropical and a number of the machines failed over the next week or two. The basement also had some electronics in and was permanently like a sauna.
The electrics were quite dodgy too - fuses still of the type where you had to whittle away a bit of wire then stick it in a strange Bakelite contraption. One winter the heating failed and the power would go occasionally, we discovered that my boss was using an air heater. I think we ran out of fuse wire and went home.
About 20 years ago PCs were not made of the stern stuff they are now, and we had a problem with PCs turning on on Monday mornings in winter - basically PCs aren't designed to cope with the temperatures you get in England in winter in buildings with dodgy (grade 2* listed and poorly maintained) sash windows so the lubricant for the hard disks was too viscous for them to start.
Then there was the time the river flooded and almost reached the power transformer in the basement.