What is the hottest part of a flame?

The light blue outer cone of a flame is recognized as the hottest part due to the complete combustion that occurs in this region. In a flame, various zones exist based on the combustion processes occurring within them. The outer cone is characterized by a blue hue, which indicates a higher temperature and efficient burning of the fuel. This is where sufficient oxygen is available for combustion, leading to higher energy releases and hotter temperatures.

In contrast, the inner cone tends to be cooler and is where the initial burning occurs without complete oxygenation, leading to some incomplete combustion. The darker areas, such as the dark red center, are indicative of lower temperatures where combustion is not as effective. Therefore, the light blue outer cone stands out as the region with the highest temperature in a flame.