Green Energy

There might also be some issues with how things are wired.

A lot of Europeans are under the impression that the American power grid distributes 110 volts. It doesn't, it distributes 220. Our transformers are center-tapped, the center tap is considered neutral and the other two hot. Measure between the hots, you get 220, which is how we power big things like stoves and HVAC and such, normal outlets are wired between neutral and one of the hots.

The US has plug and socket standards for 220. You'd think you could take something like a British kettle, nip the weird British plug off of it, put an American 220 plug on it, and plug it into one of those 220 sockets, right? A resistive heater like a kettle doesn't care about the AC frequency. It might care that what it thinks is the Neutral wire has 110V potential from Ground.