In our department at Bell Labs, we had a big machine room with a bunch of VAX computers in it (whopping gigantic 1 MHz computers that we all shared. Hehe.) Power failures were so annoying that we decided to buy a big uninterruptable power supply that filled an office-sized room with batteries and racks of electronics. Now we could run our computer for a day or two without outside power!
One day, we had a big power outage in the area. It was then that we realized that when the power goes out, the airconditioning goes out too! Actually I realized that, when I went in the machine room and it was about 95 F. No problem...it was winter, and we opened windows and set up some fans to blow cold air into the room. We felt so smug...
...until our uninterruptable power supply shut itself off. We forgot that it needed air conditioning too, and its little room had gotten over 100 F.