Source: https://www.youtube.com/watch?v=XW7CACDE-oU There's been a variety of threads here that (in part) discuss fire temperatures, but I thought it would be worthwhile to focus on WTC7 in the light of the Hulsey presentation, and the importance of fire spread and temperatures to the analysis of possible collapse sequences. This is largely information for context, and I draw no conclusions from it. There's a large number of factors to consider when looking at fire temperatures. Of primary interest here are the "upper gas temperatures" which are the temperatures of the "air" (the gas in the room, a variable combination of normal air, smoke, carbon dioxide, water vapor, and other products of combustion) above the flames. Here's some numbers for context. I'll try to use °C throughout the thread for consistency. https://www.doctorfire.com/flametmp.html "Flashover" is the point at which the room is full engulfed in fire, rather than local items in the room burning. It's the start of the "Fully Developed" fire, which will burn with maximum temperatures for some time. http://fire.nist.gov/bfrlpubs/fire02/PDF/f02082.pdf The fires shows here appear to be fully developed with good ventilation. This is reasonably consistent with NIST's simulation. (NCSTAR 1-9 page 384-5, pdf 450-1): But there's also considerable variation on the simulation, just with a change to the ceiling tile system, we get at quite different fire pattern. These are both simulations, not reality. However it seems quite reasonable that there would be areas of 900-1000°C upper gas temperatures for some time around the floor systems to the east and north of column 79. Of course gas temperature is not steel temperature. There has to be a thermal transfer of the heat from the hot gas to the steel, often via the fire protection coating.