Depends on who you ask! A one amp fuse and a GFI should cover the basics. Put it in a weather tight box if its possibly going to get wet.
For a three wire cord with built in GFI on the cheap stop by garage sales or thrift stores and pick up a modern hair dryer for a couple of dollars. The cord has that built in GFI all wired up for you!
I often buy outdoor circuit breaker boxes for things that need to work in damp or wet environments. Mount the heat sink on the side some place and use silicone sealer to make it leak proof and your basically weather proof and tamper resistant and
the fuse and GFI cover everything else as far as the NEC code rules are concerned.
Pandora be dammed! Go have some almost educational fun!