I just called Mousekeeping and asked for a tea kettle - it was brought up to the room within about 10 minutes.
I should say, don't bother using the "Front Desk" button on your phone as I did initially. Since this actually goes through to a call centre, they had no idea what I was talking about. Firstly they didn't know what a kettle was - I had to actually describe what this mystical device did and then the person on the end said "oooooooh a TEA kettle"(!!), then proceeded to tell me to use the stove, despite the fact I was in a Poly studio, none of which have stoves. Mousekeeping knew straight away and brought one up.