iPhone 18 pro heating up

That’s completely normal of camera operation to produce a lot of heat. This is especially true of higher resolution and higher frame rate recordings. Camera operators also tend to set screen brightness to maximum which produces even more heat. What you’re experiencing is absolutely normal.

There are external coolers that can be attached that help with the dissipation of the heat. I turn off Bluetooth, WiFi and cellular when recording to reduce heat and distractions and improve battery life.

When is it heating up? Is when using the camera, gaming, streaming video, updating iOS or several days afterwards?

The more details you can provide, the better we’ll be able to more accurately diagnose the issue and help guide you through it.