The Other Extreme
Went to site on a Friday Afternoon to investigate discover why the network was slow on Monday mornings & a bit better each other morning of the week at a Doctors surgery.
The answer was evident in about 30 seconds, the router, switches, VPN box & access points were all kept in a kitchen wall cabinet full of medical items, left open during the day.
"Do you close this at night?"
"I know what your problem is""
"What?" (Disbelieving tone)
"You're cooking your kit, overnight & the weekends, when you open the door each morning it gives the equipment chance to cool down!"