What Actually Is Fire? The Answer Is Stranger Than You'd Think

The warmth we feel from a fire comes from energy as it radiates outwards in the form of heat. The hot gas products rise because they are less dense than the surrounding, cooler air. The gases carry with them soot particles that glow yellow-orange because of their high temperature.

In a bushfire or campfire, it is the glowing soot that we experience as flames. Flames actually extend well above where we can see them. As the soot moves higher up, it cools and emits light in colours that we cannot see, such as infrared light.