Fire has the nature of flaming up. This is what people usually think.
When you burn moxa cones on the skin, you will find the fire flaming up first. However, when you pay more attention to it, you may notice it feels like sucking up the skin with heat. It also feels like something pulling down with heat being drawn in. I have several experiences that moxa cones flied or exploded in the air while they were burning down on the skin. Would it be that Qi in the body is pushing it back?