Why is iPhone 13 pro max super hot?when it’s charging.

Hi Leozhu0629,

Welcome to Apple Support Communities. We understand that you're having an issue with your iPhone 13 Pro Max when charging. We'd like to help.

It can be expected that your device may seem warmer that usual during certain things, charging included. Check out this resource to learn about other times. Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures

If you ever get a temperature alert, this resource will also give you steps to help with that.

Let us know if that helps.

Take care!