High temperatures make data center managers break out in cold sweats. Even though the thermostat may read a comfortable 76ºF, customers at colocation facilities say, “There must be a problem here, this room is so hot.” So many people suppose that data centers should feel cold, but few question why. The attitude in data center operations has been to follow the conventional wisdom; no one ever got fired for having a cold data center. Well, maybe someone should be fired. Data center operators are wasting billions of dollars in capital and operating expenses and creating millions of tons of carbon dioxide by routinely cooling their computers too much.