One of the most common problems I used to see as an Apple technician was iPhones that were overheating. Sometimes an iPhone felt just a little warmer than it should, and other times the back of the iPhone was so hot it felt like it might burn your hand. Either way, if you’ve got a hot iPhone, iPod, or iPad, it means there’s something wrong. Let me guess:
Your iPhone’s Battery Is Draining Too? You Don’t Say!
If you’re looking for the best ways to improve your iPhone battery life, check out my most popular article, “Why Does My iPhone Battery Die So Fast”, for tips that have already helped millions of people. In this article, I’ll explain why your iPhone is getting so hot and show you exactly how to fix it. If you don’t care about the why, that’s OK: You can skip right to the fix.
Why Is My iPhone Overheating?
As you’re aware, your iPhone is a tiny little computer you carry around with you everywhere you go. It even has almost all of the same components as your computer – they’re just really, really small. You may also have noticed that unlike your computer, your iPhone doesn’t have have a fan, or any moving parts for that matter.
That’s not a problem, until something goes wrong. If you were to open up a desktop computer (preferably someone else’s), you would see a bunch of fans, but only one component would have a giant heat-sink and a fan plopped on top of it: the CPU. The part of your computer that heats up the fastest is the CPU, and the same goes for your iPhone.
Your iPhone is overheating because its CPU is revved up to 100%, all the time!
Here’s what I mean by that: The CPU of your computer or phone is a tremendously powerful chip, and it’s a lot like the engine of your car. When does your car use the most gas? When it’s accelerating. When you step on the gas, your car revs up until you achieve a cruising speed and let off the pedal. It takes a lot more work for a car to accelerate than it does to cruise.
How often do you put the “pedal to the metal” when you’re behind the wheel? I never do. Why? Car engines are very powerful, capable of accelerating very quickly. What would happen if you held the pedal to the metal for hours and hours, pushing the engine as hard as it can go? The engine would overheat and use a lot of gas. That’s exactly what’s happening to your iPhone.
Your iPhone’s CPU is so powerful that it rarely uses 5% of its capacity. If you’re reading this page using Safari on your iPhone, your iPhone should be nice and cool: You’re coasting. When you open an app like Safari, just like accelerating from a stop, your iPhone uses more CPU to get things going but very little once the app is loaded.
Your iPhone is overheating because the CPU is revved up to 100% even when the screen is off and it’s in your pocket.
In 99% of cases, when your iPhone is hot, you have a software problem. That being said, if you dropped your phone in a bucket of water and then it started overheating, you may have a hardware problem. If your iPhone is dry, keep reading:
Unlike your car which has just one driver that controls the engine, the iPhone has a lot of “drivers”, or apps, each of which run simultaneously and have their own “accelerator pedals” capable of revving the CPU all the way up to 100%. One of your apps has gone rogue and it’s holding the pedal to the metal. Your mission, should you choose to accept it, is to find out which app is misbehaving and put a stop to it.
You’re the detective, and I know you can handle the job. I’m going to tell you exactly how to determine which app is causing your iPhone to overheat and how to put a stop to it. If you have questions, post them in the comments section below and I’ll help you along the way. We’ll start with the simplest solution and if the problem persists, I’ll show you how to hit the hot iPhone problem with the “big hammer” so we know it’s fixed.
How To Diagnose A Hot iPhone
First things first: We need to lighten the workload on your iPhone as much as possible, so let’s close out your apps. Double tap the Home Button (the circular button below your iPhone’s display), and swipe each app (except this one, if you’re reading on your iPhone) off the top of the screen. When you’re done, tap on Safari and come right back.
How Many Apps Have Been Crashing On Your iPhone?
Next, ask yourself, “When did my iPhone first begin to overheat? Was it right after I installed a certain app?” If so, that particular app may be the offender. Need a hint? Head to Settings -> Privacy (scroll to the bottom) -> Diagnostics & Usage -> Diagnostic & Usage Data for a list of everything that’s been crashing on your iPhone.
It’s normal to see a few entries in this list because log files end up here too, but if you see the same app listed over and over again, you’ve got a problem with that app. Note: If the problem has been going on for a while and you don’t know which app started the problem, that’s OK too – just skip down to the next step, “Software Updates”.
Not all iPhone apps are created equal. With over 1 million apps in the App Store, you can be sure there are a few that have a bug or two. If you can, try downloading a different app that does essentially the same thing. For instance, if you downloaded “Bird Sounds Pro”, try “Songbird” or “Squawky”. If you can’t afford to try a different app, try deleting it and reinstalling it from the App Store. To delete an app, press and hold on the app icon until it starts to wiggle and tap the black x that appears. Then head to the App Store and download it again.
Next question: “Are there any software updates available for my iPhone?” Apple periodically releases software updates that address issues that arise, some of which can cause certain apps to misbehave and your iPhone to get hot. To check, head to Settings -> General -> Software Update. If an update is available, try installing it – it might fix your problem. Note: If your iPhone says the update cannot be installed because there isn’t enough storage space, you can plug your iPhone into a computer with iTunes and use the computer to update your software. In other words, if you use a computer to upgrade your iPhone software, you won’t have to delete anything to free up space on your phone.
Reset All Settings
If you’ve tried the steps above and the your iPhone’s still getting hot, Reset all settings by heading to Settings -> General -> Reset All Settings. Tapping ‘Reset All Settings’ clears out Wi-Fi passwords (so make sure you know yours before you do it), resets your wallpaper, and restores other settings to their defaults within the Settings app. It doesn’t delete any of the data on your iPhone. I’ve seen it fix problems with misbehaving apps.
The Big Hammer: Restore Your iPhone
If you’ve done all the steps above and your iPhone still gets hot, it’s time to hit the problem with the big hammer. You’ve got a deeper software problem that needs to be eradicated. We’re going to backup your iPhone to iCloud, restore your phone using iTunes, and restore using your iCloud backup. You could also use iTunes to backup and restore your phone, but I’ve seen better results “in the field” using iCloud. Apple’s support article shows how to set up and restore from an iCloud backup in 3 steps. If you (like so many others) have run out of backup space on iCloud, I’ve written another article that explains how to fix iCloud backup so you never run out of space again.
Next, use iTunes to restore your iPhone to factory settings. After it’s done and your iPhone says Hello on the main screen, detach your iPhone from the computer (yes, this is absolutely OK to do) and follow the steps in the Apple support article to restore your phone from your iCloud backup.
Ahhhh… I Feel Better Already!
By this point, your iPhone has been through the wringer and in 95% of cases, your iPhone’s fever has lifted. It’s back to its old self again, relieved that its engine doesn’t have to keep running at 100%. To learn how to get even more battery life out of your iPhone, check out my article about why iPhone batteries drain so quickly.
I wish you all the best and I look forward to hearing from you. Feel free to post any questions and I’ll do my best to help out along the way.