This is a heart burning in the fire. The flame is orange and the heart is red. This emoticon can best represent desire or thirst, or love that burns past and moves on, or passion, strong feeling, or extended to represent rebirth.
In addition to the emoji depicted by JoyPixels platform, the flame burns behind the red heart; The flames depicted on other platforms are scurrying around, almost surrounding the hearts in all directions. The Emojipedia platform even ignited four flames in front of the red heart, showing a burning situation.