Hot Spots, Temperature Variations

When the thermostat on the wall reads 72 degF, the natural tendency of most people is to assume this means that the room is 72 degF everywhere.  But of course, this simply isn't the case; temperatures can vary by 10 degrees or more in a room, and variations of 20 degF inside server cabinets are common.  It is good practice to check different areas of the room and monitor your server room's temperature with several sensors at multiple locations - otherwise, equipment on one side of the room might be running hot while equipment on the other side is well within normal limits, and you might never know until it's too late.