Note that it’s normal for Smartphones to get warn while it’s been used, especially when used for heavy stuffs like gaming, streaming or Internet, however it becomes alarming if it gets extremely hot,
The possible causes are bad battery, or operating the phone while it’s been charged, so you will have to ascertain when the phone is usually gets hot, if it’s always hot even during a moderate use, then you might need to change the battery
So Practically you will need the service of an experienced phone repair engineer, you can click here to request for our phone repair service, because at Chrisrepair.com we offer swift and hassle free phone repair services.