Is a GFCI required for fans that are temporarily connected to an extension cord?

Plugging the cord of the fan into an extension cord which is then plugged into the permanent wiring of the building that has grounding protection in the outlet would seem to provide adequate protection, but since that extension cord is considered to be temporary wiring, the fan would need a GFCI per 1910.304(b)(3)(ii).

However, OSHA discusses this topic in a December 21, 1999 Letter of Interpretation which says:

“For example, if a GFCI-type receptacle is used, it must be visibly marked “No Equipment Ground,” and equipment required to be grounded may not be used in the ungrounded, GFCI-type receptacle. However, many appliances (i.e., lamps; toasters; televisions; double insulated appliances) and tools (i.e., double insulated tools; tools supplied with a low voltage isolating transformer) are not required to be grounded and they may be used in an ungrounded, GFCI-type receptacle. The GFCI feature of these GFCI-type receptacles provides additional electrocution protection in the event of misuse (i.e., a floor buffing machine is powered by a 3-prong plug from a properly marked and wired ungrounded, GFCI-type receptacle).”