I was wondering why the Kill-A-Watt wattmeter that I normally leave things in the room plugged into was beeping. Turned out that having an electric kettle and a space heater both on on a circuit were enough to drive the power usage over the 1800W that a normal US household circuit can provide, and that apparently the thing beeps in that case. It let me flip off the kettle before the circuit breaker flipped, which was nice.

I think I might look into a low-wattage, vacuum-insulated (to help compensate for the fact that the heat will have to be put into the water over a longer period of time) kettle.