Heating is a common problem for most of the Xiaomi phones. It is normal for the device to heat up after 30 mins or more of continuous use like playing games, surfing internet or downloading a huge file or using some app which utilises much of the memory space and drains battery, but many users have complained to have faced heating problem even if they are not using the phone to such extent.
Another thing we should keep in mind, that it is a metal body phone(anodized aluminium), so it will heat up more than a plastic body phone.
By the help of MIUI built-in feature of checking temperature,you can check out the actual temperature of battery easily. Try following steps:
Settings -> Battery -> Power
If the temperature is within 45 degree Celsius then it is ok for Redmi phones.
Here are some ways you can opt for to prevent the excessive heating for Redmi4.
Turn off auto start for applications which you do not use regularly. You can try that off by the following way:
Settings -> Permissions -> Autostart -> Turn "Off" Autostart
Close the background applications which are not needed by Settings > Installed apps > Running > Select the app > Tap on Stop button.
This not only saves battery but also helps in lowering the temperature
Turn off system animations and also avoid using a wallpaper with animation. Instead, chose a static wallpaper. You can turn system animation off by
going to the following path: Settings -> Battery -> System Animation -> Hide System Animation.
Choose Power Saving Mode to decrease battery usage and also reducing the temperature. But it will restrict many features of your phone and you might not want to choose this.
Turn of Wifi, GPS, internet, Bluetooth when you are not using these. Also, try to avoid playing heavy games on your Xiaomi Redmi4 as this is a budget phone, so the hardware is not that great.
Lastly, keep your MIUI(MI User Interface) updated at all times. You can check for the latest updates at Settings -> About phone -> System Updates.