I'm quite surprised I have never come across one of these before, since a little web research shows them to be quite common--a Sylex candle warmer! patent pending.
It's quite simple: a small candle in a lovely glass container warms the metal lid, keeping you pot of coffee or tea warm. Lovely!
On a cold, February day, what more can you ask for? I certainly could not resist it. I'm sure with a little flame inside, it's even more lovely...