I used this code from within the game to get those high frame rates:
Com_Fixedtic -1 (Removes 60 FPS Limit)
GPU and CPU get extremely hot when running like that for more than an hour. I even had my Doom 3 screen in a small window so I can monitor the temps that are displayed in the System Tray while I play. Normally under the 60fps rate, GPU gets like 60 something while the CPU runs around 42-45 degrees consistently.
Once I get that game to run at more insanely high frame rate for a long period of time, it naturally gets hot. What an experience though. FIrst time this ever happens to me. Now I know why they limit it in the first place. Yeah, I am using stock cooler but I'm not going to be playing at those high rates anymore. Going back to 60fps.