Watch these videos and be amazed.  No, it is not so hot, the silica is supercharged.  If you watch carefully you can see the vapors coming out and spraying the cars…laying down a layer of silica……………….

Note that each swipe of the flame is about 4 to 5 inches, so a lot of overlap, no section is missed.  Also, sometimes you see a spark, this is a quick burning off of some surface impurities.  Great action.