Make sure that the GFI in your bathroom is actually working! And never use an extension cord from a non-GFI outlet for any purposes in a wet location!
http://www.bbc.com/news/uk-39307418
Sad, sad, sad.
(Not all GFIs are properly wired… Do test them. The house we are buying has a Jacuzzi tub that is NOT on a GFI - that tub will go).