You are correct. The blue or purple part of the flame is by far the hottest. In school, we use a yellow flame as a "safety flame" because it a lot less dangerous. There are even games some stupid people play that involves swiping your hand through the yellow part. You hand will get burt, but it nobody has ever been burnt or hurt from this.
Actually, the very hottest part of any flame is at the very tip of a blue flame. Never ever stick your hand in this part. It is not the white part of the flame and this is not where the saying "white hot" came from.
Once looked at thermal imaging of flame for science. Sounds thrilling doesn't it?
· 10 years ago