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Why Your Phone Overheats and How to Cool It Down

October 15, 2026 · Marion Phone Repair

A phone that gets warm during heavy use is normal. A phone that gets uncomfortably hot, displays a temperature warning, or shuts itself down is overheating. This can happen during gaming, charging, or even when the phone is sitting idle. The causes range from a demanding app to a failing battery, and the fix depends on which one it is.

What counts as overheating

Phones are designed to operate between about 0 and 35 degrees Celsius (32 to 95 Fahrenheit). Warmth during a video call, navigation, or gaming is expected because the processor is working hard. Overheating is when:

• The phone displays a temperature warning and limits functions (iPhone shows a black screen with a thermometer icon; Android shows a warning popup)
• The phone feels too hot to hold comfortably against your face or in your hand
• The phone throttles performance noticeably, becoming sluggish or pausing downloads
• The phone shuts down on its own to protect internal components

External causes

Start with the environment before blaming the phone itself.

Direct sunlight and hot surfaces

A phone left on a car dashboard in summer can reach 70 degrees Celsius internally within minutes. The screen, back glass, and metal frame all absorb heat. If the phone overheats from sun exposure:

1. Move it to shade immediately
2. Remove the case to let heat dissipate
3. Do not put it in a refrigerator or freezer. Rapid temperature changes can cause condensation inside the phone, leading to moisture damage. Let it cool gradually at room temperature
4. Do not charge it until it has cooled down. Charging generates additional heat

Thick cases

Cases that cover the entire phone with thick material trap heat. Phones dissipate heat through their back surface, and a bulky case acts as insulation. If your phone consistently runs hot, try using it without the case for a day to see if the temperature drops. Consider switching to a thinner case or one with ventilation cutouts if overheating is a recurring issue.

Software causes

A single app using too much CPU

One misbehaving app can keep the processor running at full speed continuously.

• Android: Go to Settings, Battery, Battery usage. Look for any app using a disproportionate amount of battery. Also check Settings, Developer options, Running services to see what is actively running in the background. If developer options are not visible, go to About phone and tap Build number 7 times to enable them
• iPhone: Go to Settings, Battery. Scroll down to see battery usage by app over the last 24 hours or 10 days. An app using 40 percent or more of battery while you were not actively using it is a red flag

If you identify a problem app, force close it and check if the temperature drops within a few minutes. If the app consistently causes overheating, check for updates, clear its cache (Android: Settings, Apps, select app, Storage, Clear cache), or uninstall and reinstall it.

Background processes

Several normal processes can cause temporary heating:

• Software updates. Installing an update involves heavy processing. The phone may run hot for 15 to 30 minutes during and after an update while it optimizes apps. This is normal
• Photo/video processing. Google Photos, iCloud, and other services upload and process media in the background. A large batch of photos can keep the processor busy for a while
• Indexing. After a major update or restoring from backup, the phone re-indexes all content. This can take hours and causes noticeable warmth
• Location services. Multiple apps continuously using GPS drains the battery and generates heat. Review which apps have location access: Settings, Privacy, Location Services (iPhone) or Settings, Location (Android)

Malware (Android)

On Android, a malicious app running crypto mining or ad fraud in the background can cause persistent overheating. Signs include high battery drain with no obvious cause, data usage spikes, and the phone being warm even when idle. Run a scan with Google Play Protect (open Play Store, tap your profile icon, Play Protect, Scan). If you recently installed apps from outside the Play Store, uninstall them.

Hardware causes

Battery degradation

As batteries age, their internal resistance increases, which generates more heat during charging and discharging. A battery past its useful life can overheat during normal use.

• iPhone: Settings, Battery, Battery Health. Maximum Capacity below 80 percent means the battery is significantly degraded. If it shows Service or a warning, the battery should be replaced
• Android: Battery health reporting varies by manufacturer. Samsung: Settings, Battery, Battery status. Pixel: Settings, Battery, Battery health. Third-party apps like AccuBattery can estimate battery health over time

Battery swelling

A swelling battery is a more serious form of degradation. Signs include the back of the phone bulging, the screen lifting away from the frame, or the phone rocking on a flat surface when it did not before. A swollen battery should be replaced promptly. Do not puncture it, and avoid charging the phone until the battery is replaced.

Charging with incompatible chargers

Using a charger with the wrong voltage or a cheap counterfeit charger can cause excessive heat during charging. Always use the charger that came with the phone or a reputable third-party charger that matches the phone's charging standard (USB-PD, Qualcomm Quick Charge, etc.).

Immediate steps when your phone overheats

1. Stop whatever you are doing on the phone. Close the active app or game
2. Remove the case
3. Turn off Bluetooth, Wi-Fi, GPS, and mobile hotspot to reduce background radio activity
4. Move to a cooler environment, out of direct sunlight
5. If the phone is charging, unplug it
6. If it is extremely hot, power it off completely and let it cool for 10 to 15 minutes
7. Do not try to cool it quickly with ice, cold water, or a freezer

Preventing future overheating

• Keep the phone out of direct sunlight, especially during charging
• Avoid using the phone while it charges if you notice it runs hot during charging
• Close apps you are not using rather than leaving them in the background
• Keep the operating system and apps updated
• Use a case that allows heat to escape through the back and sides
• If you game on your phone frequently, take breaks to let it cool between sessions

Phone overheating repair in Marion

If your phone overheats regularly despite trying the steps above, the issue may be hardware related, most commonly a degraded or swollen battery. Marion Phone Repair diagnoses overheating issues and handles battery replacements for most iPhone and Android models.

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