Flame throwers in war.

In WW 2, American soldiers In the South Pacific jungles I believe ,were probably saved by using Flame throwers against the Japanese soldiers who hid in caves among other places.  These flame throwers threw fire about 30 feet or so.  Anything in their way was burned to a crisp.  This included the Japanese soldiers.  If they didn't die instantly, then a slower death must have been agonizing.  I need to ask,  how this compares to poison gas and its victims?  Or is it fair to even to raise the question?................marge