The core of the sun is actually the hottest part. Here's why:

* Nuclear Fusion: The core is where nuclear fusion takes place. This process, where hydrogen atoms fuse to form helium, releases an immense amount of energy in the form of light and heat.

* Pressure and Gravity: The immense pressure and gravity at the sun's core create extreme temperatures, reaching millions of degrees Celsius.

* Energy Transmission: The energy generated in the core is then transmitted outward through the sun's layers, gradually decreasing in temperature.

So, the temperature of the sun increases as you go deeper into its core.