I read the first comment and see her point, but 'warmth' is a very subjective word which lends itself to many interpretations.
My first impression was of a wall sconce, with a lit candle inside, throwing off a soft and gentle light. You used warm colors which are slightly toned, creating more a sense of embers than of fire (....hence the title). You've succeeded so well in making this image glow with gentle heat, I imagine that I should be able to hold my hands out to the monitor and feel the warmth throught the screen.