Re: Fire suppression and high-value electronics
A very large computer hall had signs on all entrances and inside "NO HOT WORKING", as the smoke detectors were very sensitive. (It was in the days of Halon fire suppressant systems of the 'get out or suffocate' variety).
One 'bright spark' (did you see what I did there?) plugged in his soldering iron. Waiting for it to get hot, the lead vapour liberated triggered the alarm. Fortunately someone was quick enough to disable the halon system before it discharged. The electrician was escorted off the premises and banned for life.
The hall did have several tens if not hundreds of millions of pounds worth of kit, and housed some UK Critical National Infrastructure as well.