The Pit Hawg is designed to suck up cold to warm fine ash. Ash takes seven days to reach a true ""cold"" state - we don't want you to wait that long. While this vacuum should not be used with hot ash or coals, should you accidentally suck up too hot of ash or a live coal, this vacuum will not catch fire. The flame-resistant filters will protect up to 1000 degrees F, while the thermal plastic components will never catch fire.