Question: Would you please tell me approximately what temperature an open hearth wood fire burns at. Answer: There are different temperatures at different parts of the fire. The hottest temperature in most wood fires are found in the red embers after the fire has been going for awhile. These temperatures are from 1200 degrees to 1500 degrees. However, since so much air is circulating around the fire, grates and other nearby object rarely exceed 1000 degrees. The gas fire probably burns at a lower temperature, with the grate also being the hottest part...around 1000 degrees. This is evident because the grates sometimes glow...and iron glows at approx 1000-1100 degrees F. The flue in both cases is usually quite cool, because of the air mixture. In colonial times, some flues were built from WOOD with a mud pack on the inside.... chances are that the normal flue temperature for such an open fire fall in the 250-400 degree range.