I think that it is time to make this a safety recommendation. The evidence is building that this is a huge potential safety hazard. The consequences of unplugging the fuel heater element are minimal, especially in temperate climates.
Problem: Fuel heater element may short and cause fires. Due to the design of the fuel system (negative pressure, poor seals, etc), air innevitably collects in the top of the fuel filter, the highest point in the fuel lines. The Fuel Heater element is also located at the top of the fuel filter head, so it is often exposed in air and can overheat. This element is not sensor controlled, but is materially designed to shut off at cetain temperatures. Also, the electrical connections may cause a short under these conditions. In any case, many pugs and elements have been show burned or shorted out. These sparks could cause fires.
Solution: The immediate fix is to unplug the fuel heater element. There are two electrical plugs located on the fuel filter heat, the heater element is the one located on the driver's side. Be sure to inspect the plug on removal for signs of shorting or listen for air leaks. If there is any sign of leaks or shorts, seek service. Other, non OEM solutions do exist.
If others dissagree or feel that this post is alarmist, feel free to comment or remove it. However, the very serious potential consequences certainly outway the simple fix.
Picture of burned out plug:
Suspicous fire pic (with suspicously missing Filter head) that may be related to this issue:
https://www.iaai-bid.com/getimage.aspx?imagetype=0&imageid=31411018