Some iPhone 5s users complained that the phone was overheating and it usually led to quick battery drain too. The problem may be caused by an app or by the phone’s software. Some have a feeling that the hardware may be blamed, but for most users software fixes have worked.
Solution 1: Identify Misbehaving Apps
There is a chance that the problem may have started after you installed a particular app. If this was the case then get rid of the app and check if your phone behaves normally then the app is to blame, but if the app did not make a difference then you must consider restoring your phone to factory settings after backing up all files.
Solution 2: Restore your phone
Back up all files on your phone either on iCloud or iTunes depending on what you are comfortable with before you restore your phone.
- Launch the Settings menu on your phone
- Tap on General and look for Reset which is towards the bottom of the screen
- Tap on Erase All Content and Settings
- Now you will see the option to erase your iPhone data. Tap on Erase iPhone and tap again on Erase iPhone in the warning message box that shows up on your screen.
- You will be prompted to enter your passcode to proceed with the erasing of all files.
Once all the files and data are erased from your phone you will be able to set it up like new. Be picky with the apps you download and identify any apps that cause sudden battery drain and remove it instantly.
If none of these work for you, then consider taking your iPhone 5s to the store and if the problem is identified to be a hardware issue then the phone may be replaced provided it is under warranty.