Whether you’re charging, gaming or recording a long video, your phone can get noticeably warm. This is mainly due to the powerful processor, the display and the wireless modules, which consume a lot of energy under heavy use.
That type of heating is usually nothing to worry about. However, it becomes a problem if your smartphone gets unusually hot when you’re hardly using it, if its performance suddenly drops, or if it fails to cool down again. Direct sunlight, a hot car or a faulty battery can also quickly push the temperature into the critical range. We’ll explain which causes are harmless, when you should take action, and what simple steps you can take to bring your smartphone back to a normal temperature.
Why does a smartphone get hot?
Not every spike in temperature indicates a fault. The key thing to note is when and for how long the smartphone gets hot: if it’s heating up even when idle, or if you notice other unusual symptoms, you should take a closer look:
| Cause | Harmless or critical? | What you should do |
| Fast charging | 🟢 Usually harmless | Avoid gaming and other computationally intensive tasks while charging. |
| Gaming, camera, navigation | 🟢 Usually harmless | Take a break in very hot weather and avoid direct sunlight. |
| Updates & cloud sync | 🟢 Normal for a short time | Give it some time after major updates or backups. |
| Poor mobile signal | 🟢 Usually harmless | If possible, use Wi-Fi or temporarily switch on aeroplane mode. |
| App using a lot of CPU power | 🟡 Monitor | Check battery usage and update or remove any apps that stand out. |
| Overheating when idle | 🟠Warning | Check battery usage and restart your smartphone. If it remains it may be time to take it to be assessed and repaired. |
| Performance drops | 🟠Safety feature | Allow the device to cool down. Many smartphones automatically throttle their performance when the temperature gets too high. |
| The casing or display is bulging | 🔴 Critical | Don’t charge or use the device at all. Don’t try to remove or press down on the battery. Contact a specialist repair centre or the manufacturer. |
When does heat become dangerous?
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If a smartphone gets too hot, it often automatically reduces its performance, dims the display or even stops charging. This thermal throttling limits further heat build-up and protects the hardware from excessive heat.
The situation is different if the device becomes hot without any apparent reason. In this case, check the battery settings to see which apps are using a particularly large amount of power, and restart the phone. If it remains hot afterwards or the battery drains unusually quickly, you may need to take it to a specialist.
A bulge in the casing or display is extremely serious: it can indicate a damaged or swollen lithium-ion battery. In the worst-case scenario, there’s a fire risk. You should stop charging or using your phone and under no circumstances try to remove the battery yourself.
An unusually hot power adaptor, cable or a charging port that has become very hot are also warning signs that should be taken seriously – disconnect the device from the mains and stop using any accessories for the time being.
If your smartphone becomes unusually hot, you should first stop using it and allow the device to cool down naturally. You should not try to actively cool it down.
| Action | Effect |
| Pause charging | Stops an additional source of heat and reduces the load on the battery. |
| Reduce the load | The processor, display and wireless modules consume less energy and generate less heat. |
| Remove the case | Heat can be dissipated more easily. |
| Avoid direct sunlight | Prevents additional heating. |
| Don‘t cool it artificially | Putting your phone in the fridge or cooling it with ice can lead to condensation and internal damage. |
Important: If your smartphone smells unusual, if the casing is warped or the battery is swollen, you should stop using or charging it immediately.
How to keep your smartphone cooler
Prolonged heat build-up can be avoided with a few simple steps. First, check your battery use and look for apps that are using an unusually large amount of power. You should update or remove any apps that stand out.
If you frequently charge your smartphone for long periods, you can also activate a charging limit of around 80 per cent: Apple has offered a fixed 80 per cent limit on all models since the iPhone 15, whilst Samsung has integrated it under ‘Battery Care’ (One UI), while newer Google Pixel and Sony Xperia models also feature similar battery care modes. A practical side effect is that avoiding the maximum charge level can significantly extend the battery’s lifespan.
High screen brightness and resource-intensive apps also drive up energy consumption. The combination of fast charging and heavy usage – such as gaming while charging – is particularly detrimental.
Tip: Look out for cooling features when buying a smartphone
Anyone who plays games frequently or carries out other demanding tasks should consider heat dissipation, as well as the processor and battery. Vapour chambers, graphite layers and well-designed casings help to distribute heat and maintain stable performance for longer.
The latest top-of-the-range models, such as the Samsung Galaxy S26 Ultra, the iPhone 17 Pro or Pro Max, feature sophisticated cooling solutions. For those who play demanding games on their smartphone, the Redmagic 11S Pro is designed with cooling as a top priority. It utilises an ‘AquaCore’ system that dissipates heat via liquid circulation and is even visible on the back. However, such specialised cooling solutions aren’t essential for normal day-to-day use.
Conclusion: When should you take your phone in for repair?
If your smartphone only gets warm while charging, gaming or using sat-nav, then cools down again, this is generally not a cause for concern. It’s normal for it to get warm under heavy use, but if it gets hot without any obvious strain, that’s a warning sign.
If the device remains hot despite a restart, the battery drains unusually quickly, or overheating occurs repeatedly, you should have it checked by the manufacturer or a specialist service centre. You must take a swollen or deformed battery seriously: stop charging and using the phone right away.
If your phone is ageing, a newer model will have better protection against high temperatures and, thanks to more efficient chips, will be more energy-efficient. Our buying guides can help you find the best phone for your needs:
Topic: Smartphone overheating? The warning signs you shouldn’t ignore (Read 2 times)
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November 04, 2025, 01:00:31 AM