Originally Posted by corporate-wage-slave

Using a hairdryer (in particular) in the bathroom isn't a good idea when mains voltage is 110v, but at 230 / 240v it is beyond foolish. The UK introduced a set of Building Regulations, initially in the 1970s, that control this issue, and in essence you are not allowed direct mains power in bathroom sockets, and there are strict rules on wiring up bathrooms. So if there is a shaver power point, this will be typically 110v, protected by RCD and insulated from the mains via the stepdown voltage transformer. Oh and a 3amp fuse just in case. It can actually be 220-240v provided it is insulated from mains, RCD and protected, often it still goes via a transformer. These Building Regulations have saved about 4,000 lives since their introduction, accidental death by electrocution in the home in the UK has almost been eliminated. Which is more than can be said for the USA. To be clear, mains electrocution at 110v when wet is still pretty serious, it can still result in death in some cases, just more slowly and painfully.