Q: iPhone 5 gets hot, drains battery.

Hello louisfromvanves,

Thanks for asking your question here in the Apple Support Communities. I am sorry you are experiencing issues with your iPhone 5 getting hot and draining the battery. Thanks for isolating the issue a bit using airplane mode. While this may seem like a hardware issue, to be sure, we are going to reset the device back to factory settings, and set it up as new using iTunes.

Before doing anything, we want to make sure your data is all safe. Please make a backup of your device using iTunes or iCloud. This article will help you do this:

How to back up your devices using iCloud or iTunes

Once your data is backed up and safe, you will need to connect your iPhone 5 to a computer, and use this article to erase it, and get a new version of iOS through iTunes:

Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings

Once it is reset, do not restore any personal data. Set the iPhone 5 up as new, and test to see if the heat and battery issues are happening without your personal data on the device. If not, we know the issue was with some data stored in the backup. You can manually bring data back using iCloud or iTunes, but do not restore from the backup as the problem may return. This article will help you sync data back to your iPhone using iTunes:

Sync your iPhone, iPad, or iPod touch with iTunes on your computer using USB - Apple Support

If the heat and battery issues do still occur with no personal data, then we need the phone hardware checked. You may wish to call AppleCare, or contact an Advisor using:

Contact Apple Support

You can also search for an Apple Authorized Service Provider or Apple Retail Store in your area from this link:

Apple find locations

Have a great day.