A bonfire built with wood and charcoal can burn at temperatures up to 2,012 degrees Fahrenheit. The color of the fire is an indicator of temperature; dark red flames are cooler at 1,112 degrees F than orange-yellow flames at 2,012 degrees F.
A bonfire becomes hotter over time, based on how much material is burnt and released as a gas. In the initial stages, fire heats wood to 212 degrees F, releasing the water within the wood as steam. When the wood dries, it releases gases, raising the temperature to 1,099 degrees F. When all of the gas is released, the wood turns to ash. Charcoal added to the mix burns carbon as well, resulting in temperatures up to 2,012 degrees F.