Speedfan can be a little misleading with it's icons.
From using SpeedFan for a few years I'm almost certain that the flame logo means it's above an average temp for your PC.
About 2 years ago, I was getting temps of ~50*C with a normal icon (the arrows). I cleaned out my PC case and put new fans in as well as starting with a fresh system and my CPU was running in the 40*C range. After a while I noticed it got up to 48*C-ish and had the flame logo -- a high average, but not worrisome.