Upon entering the furnace room, Sly was contacted by Bentley, who told him that the temperature readings are off the chart and that it must be the power source for Raleigh's storm machine.
The area was filled with furnaces and doors that emitted flames. Sly had to close them in order to pass safely. There were also machines that Sly needed to run on to operate certain contraptions such as the conveyor belt. Once he found the treasure key, he exits the area.