Phone Overheating? What's Normal, What Isn't, and What to Do

Where the line is

Ignore the absolute temperature and look at the circumstances.

Cooling it down right now

In order of how much each one helps:

1. Take the case off. A thick case is insulation. This is the single most effective thing you can do in the moment, and people almost never think of it.
2. Get it out of direct sun. A phone on a car dashboard or a café table in summer heats far beyond what it can shed. Shade beats everything else.
3. Stop charging if it's plugged in.
4. Close what you're doing — especially navigation, games, or the camera.
5. Turn on airplane mode. This does more than people expect: if you're in an area with poor signal, the radio is transmitting at full power and generating real heat. See the section on idle heat.
6. Turn the screen brightness down, or turn the screen off entirely.
7. Put it on something that conducts heat away — a metal or stone surface, not a bed, sofa, or your lap.

Give it ten minutes. A phone that doesn't cool down after ten minutes of doing nothing has a real problem.

The cooling method that causes damage

Hot while doing nothing

This is the case worth investigating, and your phone already logs the cause.

• Check battery usage by app. An app with hours of background activity and minutes of screen time is your culprit. Our battery drain guide shows exactly which screen to open and how to read the foreground/background split — heat and drain are the same investigation.
• Weak signal. Genuinely underrated. In a basement, a lift, or a rural dead zone, the phone transmits at maximum power continuously. This heats it noticeably and empties the battery. Airplane mode, or Wi-Fi calling where available, fixes it instantly.
• A stuck sync. A photo backup that keeps failing and retrying, or an email account with wrong credentials, will loop forever. Symptom: warm while idle, battery falling overnight. Check that your backup has actually finished rather than just being switched on.
• You updated recently. After a major OS update the phone re-indexes photos and re-optimises apps for a day or two, and runs hot throughout. This resolves itself — leave it charging overnight before concluding anything is wrong.
• Restart it. A stuck background process survives an awful lot and is cleared by a reboot. Free, takes a minute, and worth doing before anything else.
• An app that recently updated. If the heat started on a specific day, check what updated then. A performance bug in one app version is common and usually fixed in the next.

Hot while charging

Some warmth is unavoidable — charging is a chemical process and it generates heat. What matters is how much, and what else is going on.

• Fast charging generates the most heat, particularly in the first half of the charge. This is expected. Phones deliberately slow down above about 80% partly for this reason.
• Never charge under a pillow or duvet. The heat has nowhere to go. This is the genuinely unsafe scenario, not merely a bad one.
• Take the case off while fast charging. Same reasoning as before.
• Don't game while charging. Two heat sources at once, and the phone can't shed both. This is the most common cause of a phone getting alarmingly hot.
• Wireless charging runs hotter than cable by nature — some energy becomes heat rather than charge. A pad with a fan, or just cable charging when you're in a hurry, avoids it.
• Check the cable and adapter. A damaged cable or a poor-quality no-name adapter can cause excess heat at the connector. If the plug end of the cable is the hottest part, replace it.
• Charging stopped and the phone says it's too warm? That's protection working correctly. Let it cool; it will resume on its own.

What the warnings mean

Phones don't just get hot and hope for the best — they progressively shed load. Recognising which stage you're at tells you how serious it is:

• The screen dims on its own and won't go brighter. First line of defence, very common outdoors in summer.
• Charging pauses. Second stage. Normal protective behaviour.
• The camera refuses to open, or flash is disabled, or video recording stops. The camera is one of the hottest components, so it's cut early.
• Performance drops noticeably — this is throttling, and it's also why a phone feels slow after 15 minutes of gaming. Our slow phone guide covers the pattern.
• A full-screen temperature warning, with everything except emergency calls disabled. Last stage before shutdown. Stop, remove the case, and put it in the shade.

None of these mean the phone is damaged. They mean the protection is working. A phone that gets hot enough to shut down repeatedly, though, is worth investigating properly — repeated heat does permanently reduce battery capacity.

Keeping it cool

• Don't leave it on a car dashboard. A closed car in summer reaches temperatures well beyond anything the phone is designed for, and this is the most common cause of real, permanent damage.
• Turn off background refresh for apps that don't need it, and set location to "while using" rather than "always" for everything except navigation.
• Use a thinner case in summer, or take it off during heavy use.
• Turn on optimised or adaptive charging so it isn't holding at 100% and warm all night.
• Keep some free storage. A nearly full phone works harder for every write, which generates heat — see our storage guide.
• Don't use it as a dashcam or a sat-nav in direct sun without shade. If you must, a vent mount keeps air moving over it, unlike a windscreen mount.

When to stop using it

Almost all overheating is a nuisance rather than a hazard. These are the exceptions:

• The back or screen is bulging, or the phone no longer sits flat. A swollen battery is a fire risk. Power it off, don't charge it, don't press on it, and take it to a repair centre.
• Any smell — sweet, chemical, or burning.
• It gets hot with nothing running, straight after a restart, and doesn't cool down.
• It shuts down from heat repeatedly in ordinary use.
• It got hot after being dropped or wet.

In those cases stop charging it and get it looked at. In every other case, take the case off, find the shade, and check which app has been running in the background.