Introduction
iPhone overheating and running slow is a common problem, especially after heavy use, a recent iOS update, or running demanding apps for long periods. If this is happening to you, you’re not alone. It’s a common complaint and easy to assume the problem is simply that your iPhone is getting old. But that’s usually not the case.
The reality is overheating and slowdowns almost always go together. When your iPhone gets too hot, iOS by design reduces processing speed to protect the hardware inside. It’s completely normal, your phone protecting itself.
The good news is you probably don’t need a new phone to fix the problem. A few adjustments to how you charge it, which apps you’re running, how much storage you’ve got free, and some settings can usually get things back on track.
This guide explains the common causes of iPhone overheating and running slow, how the two problems are connected, and the most effective ways to fix them. This article is reviewed using Apple’s official support documentation, publicly available technical information, and real-world troubleshooting practices.
Why Do iPhone Overheating and Running Slow Happen Together?
People often consider these separate problems, but usually one causes the other. Your iPhone’s processor adjusts its speed constantly based on what you’re doing and its temperature. Gaming, video editing, GPS navigation, video calls, and 4K recording all demand a lot of processing power, and that generates heat.
Apple explains how the iPhone manages temperature. Apple has built-in thermal protection to prevent overheating. Once the internal temperature crosses a safe limit, iOS reduces processor performance to help protect the internal hardware. This is called thermal throttling, and it protects the battery and other components from damage.
That protection is useful, but it’s also exactly why an overheated iPhone feels slow. If overheating keeps happening over time, it can degrade the battery faster too. And a worn battery brings its own slowdowns, so the problem can get worse over time.
Common Reasons Your iPhone Is Overheating
If you’re dealing with iPhone overheating and running slow, the good news is that you probably don’t need a new phone. Try these fixes one at a time.
Heavy Gaming
Graphics-intensive games put a heavy load on both the processor and GPU, often for extended periods. The longer you play, especially while your iPhone is charging, the more heat can build up.
Streaming High-Quality Videos
4K and HDR streaming keeps the screen, processor, wireless radios, and speakers all running at once. A short session is fine, but hours of continuous playback will warm the phone up.
Using GPS Navigation
Navigation apps constantly check your location using GPS, cellular data, Bluetooth, and the screen. Full-screen brightness and charging your iPhone at the same time, especially while using navigation in the car, can build up heat quickly.
Video Recording
Recording in 4K or at high frame rates means constant image processing and saving data to storage. Long recording sessions, especially outdoors on a warm day, heat up your phone quickly.
Video Calls
FaceTime, Zoom, and WhatsApp calls use the camera, mic, screen, speakers, processor, and your internet connection all at the same time. A long meeting generates noticeably more heat than a regular phone call.
Background App Activity
Sometimes an app keeps syncing photos, uploading files, or refreshing content after you’ve closed it. You won’t notice this happening, but it keeps the processor busy, and the phone gets overheated.
Environmental Temperature
Where you use your phone matters too. Direct sunlight in summer heats it up fast, and leaving your iPhone in a parked car is even worse, as temperatures inside can quickly rise beyond Apple’s recommended operating range. According to Apple, the iPhone is designed to operate best in ambient temperatures between 0° and 35 °C (32° to 95 °F). Using it outside this range may temporarily affect performance.
Even normal tasks feel more demanding in hot environments because the phone can’t cool itself as efficiently. If your iPhone is overheating and displays a temperature warning, stop using it and let it cool down before continuing
Why Is Your iPhone Running Slow?
A slow iPhone doesn’t mean it needs replacing. If your iPhone is running slow, the cause could be software, hardware, or a combination of both.
Low Available Storage
If your iPhone is running slow, freeing up storage is one of the first things you should try When storage runs low, iOS has less room to work with for temp files, caches, and background tasks. That affects how fast apps launch and how smoothly you can multitask. Try to keep 15–20% of your storage free.
Too Many Background Processes
Beyond the app activity already mentioned, things like widgets, photo analysis, and pending app updates quietly compete for processing power. None of them is a big deal alone, but together they add up.
Outdated Apps
Older versions of apps can have bugs or may not be well optimized. Developers regularly release updates that fix bugs, improve performance, and reduce unnecessary processor usage, so keeping your apps up to date can genuinely help.
Software Bugs
Occasionally, an iOS update comes with a hidden drawback. It might make your phone’s processor work harder or eat through battery life quicker than before. The good news is that Apple usually resolves these issues in the next update, so it’s a good idea to keep your iPhone up to date.
Aging Battery
An aging battery is another reason your iPhone is running slow, especially if iOS has started limiting performance to prevent unexpected shutdowns. Apple states that lithium-ion batteries naturally lose capacity over time and eventually become less capable of delivering peak power.
Research from Battery University also explains that heat is one of the biggest factors that accelerates lithium-ion battery aging. When battery health drops to a certain point, iOS may temporarily reduce processor performance to help prevent unexpected shutdowns. Not every older iPhone reaches this point, but it’s a real factor in some slowdowns.
Does Charging Cause Overheating?
If your iPhone is overheating while charging, the cause is often fast charging, wireless charging, or using demanding apps at the same time.
Apple says that some warmth during charging is expected, particularly when fast charging or using wireless charging. Fast charging delivers more power to the battery in less time, so it gets hotter. Wireless charging also produces heat. Some energy is lost as heat during the transfer.
But your iPhone shouldn’t get too hot simply from charging. Using an uncertified charger, a broken cable, a heavy case, or gaming while charging can all cause the temperature to rise more than usual. If possible, avoid heavy tasks while your phone is charging, especially with fast charging.
Can Software Updates Make Your iPhone Hot?
Yes, if your iPhone is overheating after an iOS update, it’s usually temporary while the system finishes background optimization. After a major iOS update, your iPhone may temporarily perform background tasks such as re-indexing Spotlight Search, analyzing the Photos library, syncing iCloud data, and optimizing apps.
Many of these optimization tasks rely on on-device AI and machine learning to organize photos, improve search, and optimize system performance. Learn more in our guide on How AI in Smartphones Is Changing Modern Phones.
This can cause the processor to work harder than usual for a few hours and this is what is making your phone feel warmer than usual. Once they’re finished, the temperature should return to normal.
15 Proven iPhone Overheating Fixes That Also Improve Performance
If your iPhone keeps running hot and feels slow, you probably don’t need a new one yet. Try these one at a time and see which one makes a difference.
Restart Your iPhone
This is the fastest solution to try first. Background processes and small glitches build up over time and make the processor work harder than it needs to. Restarting your iPhone closes temporary processes and clears minor software glitches, which can resolve overheating or slowdown caused by apps or temporary system activity.
Install the Latest iOS Update
Apple releases bug fixes, security patches, and performance improvements through updates. If you’re behind, updating can solve overheating, battery drain, or sluggishness. Just know your phone might run warm for a few hours right after a major update while it indexes and optimizes in the background, that’s normal.
Update Your Apps
An outdated app can use more resources than it should because of bugs or poor optimization. Keeping your apps up to date reduces the chances of a single app slowing down your entire iPhone.
Close Apps That Are Working Hard
iOS generally manages background apps well on its own, but heavy ones like games, navigation, video editors, and calling apps can keep using resources after the process is completed. Close them and give the phone a few minutes to settle.
Reduce Screen Brightness
The display uses a lot of power. Running it at full brightness for a long time produces heat and drains the battery faster. Turn on Auto-Brightness or lower the screen brightness manually when you’re indoors.
Remove Thick Cases
Cases protect against drops, but thick or rugged ones can trap heat inside. If you’re gaming, recording long videos, or fast-charging, take the case off for a bit to let heat escape.
Avoid Using Your iPhone While Charging
There’s already some heat from charging. If you add gaming, video editing, or a long phone call at the same time, the processor and battery have to work harder, creating even more heat. Don’t use your iPhone too much while charging it.
Free Up Storage Space
A nearly full storage makes iOS less responsive since temporary files and system processes need room to work. Delete unused apps, clear duplicate photos, remove big downloads, and back up old videos to the cloud. Aim to keep 15–20% free.
Check Battery Health
Aging batteries can’t deliver maximum power when needed. If health has dropped considerably, iOS may reduce the performance to prevent shutdowns. Check battery health in settings; if it’s badly degraded, a replacement often brings back most of the original speed.
If your battery health has dropped significantly, our iPhone Battery Health guide explains what the percentage really means and when replacement is worth considering.
Limit Background App Refresh
A lot of apps refresh content even when you’re not using them. Turning this off for apps that don’t need it reduces processor load, saves battery, and keeps the phone cooler.
Disable Unnecessary Location Services
GPS is one of the most power consuming features on the phone. Apps that track your location constantly increase both battery drain and heat. Only allow it for apps that actually need it, and switch permissions to “While Using the App” where you can.
Avoid Direct Sunlight
Even a healthy iPhone will overheat in hot outdoor conditions. Sunny dashboards, the beach, and walking around in direct sun, all of these keep the phone warm. Keep it shaded, and never leave it in a parked car.
Use Certified Chargers
Cheap charging accessories often don’t regulate power properly and can run hotter than they should. Use an Apple-certified charger or a high-quality charger from a trusted third-party brand.
Reset Settings if Necessary
If the overheating started after you changed settings or transferred data from another phone, resetting the settings can resolve issues. This will not affect your personal files. It simply resets settings such as Wi-Fi passwords, wallpaper, and system preferences.
Let Your iPhone Cool Down Naturally
If your iPhone gets too hot, stop using it for a while and let it cool down by itself. Do not store the device in a refrigerator or freezer. Sudden temperature changes may cause condensation inside the device and damage it. Instead, store it in a cool, well-ventilated place until it has returned to normal temperature.
These simple iPhone overheating fixes solve the problem for most people without the need for repairs.
When Overheating Could be Hardware Problem
Software explains most overheating cases, but not all of them. If your iPhone gets extremely hot just from browsing or texting, or it overheats even after a factory reset, it’s worth getting it checked out.
Watch for other warning signs too like fast battery drain, random shutdowns, charging that won’t work, or any swelling around the battery. Don’t ignore these, they can point to real battery or hardware damage.
Final Thoughts
iPhone overheating and running slow doesn’t usually mean your phone has a serious hardware problem. In most cases, the cause is demanding apps, low storage, software bugs, background activity, or an aging battery rather than a serious hardware problem. The issue can be fixed with a few simple changes.
Keep iOS and your apps updated, leave enough free storage, use certified chargers, avoid heavy tasks while charging, and keep an eye on battery health. Do that, and your iPhone should run smoothly for a long time. For more ways to extend your battery’s lifespan, check out our complete iPhone Battery Health guide.
If iPhone overheating and running slow continues even after trying these fixes, it should be checked by a technician. Catching the problem early saves your battery and keeps the phone reliable for longer.
Frequently Asked Questions
Why is my iPhone overheating and running slow?
Usually it depends on how you’re using it. Gaming for a long time, using GPS, recording video, or running a lot of apps in the background can all generate heat. Low storage space and an aging battery can also contribute to the problem. Once your phone gets too warm, iOS actually slows itself down by design. It’s a built-in safety feature to protect the internal components.
Is it normal for an iPhone to get hot while charging?
It’s completely normal for your iPhone to get a bit warm while charging, especially if you’re using fast charging or wireless charging. That’s to be expected. If it becomes too hot, that is not normal. Most of the time, that means you’re using your iPhone while it’s charging, your case is trapping heat, or there’s a problem with your charger or cable.
Can an iOS update make my iPhone overheat?
Yes, and it’s temporary. Right after installing a big iOS update, your phone works overtime in the background, reindexing everything, optimizing apps, and that kind of thing. Most iPhones return to normal temperatures within several hours after a major update, although background indexing can continue for up to 24 hours depending on the amount of data stored on the device.
Does low storage make an iPhone run slower?
Yes, it can. When your storage is nearly full, your iPhone doesn’t have sufficient space for temporary files and background processes, which can negatively impact performance. Try to keep at least 15–20% of your storage free.
How can I stop my iPhone from overheating?
A few easy habits can help prevent overheating, such as keeping iOS and your apps updated, avoiding heavy usage while the phone is charging, lowering your screen brightness, removing thick cases during demanding tasks, closing background apps, and using Apple-certified chargers.
When should I be concerned about an overheating iPhone?
If your phone’s overheating just from texting or browsing, keeps showing temperature warnings; has random shut downs, drains battery very fast, doesn’t charge properly, or you notice the battery looking swollen, that is a sign to have it checked by a professional. Those are signs of a real battery or hardware problem, not just normal heat.