My iPhone 13 mini is heating up during imo calls

📱Facing iPhone heating issues? Here's what worked for me on my iPhone 12 Pro:

1️⃣ Backup on iCloud/iTunes

2️⃣ Log out of Apple ID

3️⃣ Erase (Keep eSIM Data)

❌ DO NOT restore from backups! Set up as new iPhone. Wait 2-3 days - no issue! That Indicates...

✅ No hardware/ iOS issue

Now...

📦 Restore data gradually

🔍 Find app/settings causing heat

My experience says this is purely caused by some third-party app that you may have installed.

I am not aware of the ambient temperature in which you are using the iPhone. However --> Keeping iPhone, iPad, and iPod touch within acceptable ...

Store the device where the temperature is between -20º and 45º C (-4º to 113º F). Don’t leave the device in your car, because temperatures in parked cars can exceed this range.

Use iOS devices where the ambient temperature is between 0º and 35º C (32º to 95º F). Low- or high-temperature conditions might cause the device to change its behavior to regulate its temperature. Using an iOS device in very cold conditions outside of its operating range might temporarily shorten battery life and could cause the device to turn off. Battery life will return to normal when you bring the device back to higher ambient temperatures. Using an iOS device in very hot conditions can permanently shorten battery life.

In addition to the advice SravanKrA provided, I'm curious to know what your Battery Health is currently? Phone calls, using the camera, streaming music/videos etc., are battery intensive tasks and the physics of batteries means when they work harder, they generate heat naturally. But, if your Battery Health is near or below 80%, the useful lie of the battery has been used and it would be time to pay Apple to replace the battery in your phone.

To check it's health, go to Settings > Battery > Battery Health