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01How hot is too hot?
A phone overheating while charging is common, and most of the time it's the phone protecting itself, not failing. Charging a lithium-ion battery always makes some heat. Fast charging and wireless charging make more.
Your phone measures its own battery temperature and reacts. First it slows charging, then it pauses, and if it gets hot enough it shows a warning and limits what you can do until it cools. Apple says iPhones work best at ambient temperatures between 32° and 95°F (0° to 35°C). Leave a phone charging in a hot car or direct sun and you're past that before the battery adds any heat of its own.
| What you feel or see | What it means | What to do |
|---|---|---|
| Warm to the touch, like a mug of tea that's cooled down | Normal, especially with fast or wireless charging | Nothing. Carry on |
| Charging slows or pauses, "Charging On Hold" or similar | Phone is managing heat | Move it somewhere cooler and leave it |
| Too hot to hold comfortably | Not normal. Something is trapping or adding heat | Unplug, remove case, let it cool |
| Temperature warning on screen | Phone has hit its limit | Unplug, turn it off if you can, cool it in the shade |
| Swelling, bulging screen, smell, hissing or smoke | Battery damage | Stop charging. Move it away from anything flammable |
02How to cool a phone down safely
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Unplug it
Take it off the cable or pad. Charging is adding heat, so stopping is the fastest fix.
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Take the case off
Cases insulate. Thick rugged and leather cases hold heat against the battery like a jacket.
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Move it somewhere cool and shaded
A table indoors is ideal. Out of the sun, off the dashboard, off the bed. A fan blowing across it helps.
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Close the heavy stuff
Games, video calls, navigation and camera recording all add heat. Close them, or turn on Low Power Mode or Power saving.
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Wait 10 to 15 minutes
Then plug back in with the case off and the screen locked. If it heats up quickly again, read on for the causes.
Fast cooling causes condensation inside the phone, and moisture near the battery and board does far more damage than heat. Let it cool at room temperature.
03Why your phone overheats on the charger
Overheating is almost always a combination of things stacking up. Remove any one of them and the phone usually settles.
- Using it while it charges. Gaming or streaming on a fast charger runs the processor and the battery hard at the same time.
- Soft surfaces. Beds, pillows and couches block airflow around the phone.
- Heat from outside. Sun on a windowsill or a car mount on the dash in summer. We cover cars specifically in phone overheating in a car mount.
- Thick or metal-backed cases. They insulate, and metal on a wireless pad heats up directly.
- Wireless charging. Some energy is lost as heat between the coils, more so if the phone sits off-center.
- Cheap or damaged chargers and cables. Poor-quality gear can deliver unstable power. If the plug or brick itself is hot, replace it. See how to spot a fake charger.
- An aging battery. Older batteries can run warmer under load.
04Wired, fast or wireless: which runs hottest?
Standard wired
- Least heat
- Slowest
- Kindest to an aging battery
Fast wired (PD / PPS)
- Warm in the first 20 to 30 minutes
- Phone tapers speed as it fills
- Fine with a proper certified charger
Wireless
- Most heat per percent charged
- Worse if off-center
- Magnetic chargers help with alignment
Fast charging is not dangerous on a phone designed for it. The phone controls the speed and backs off as it warms. The trouble is fast charging plus gaming plus a thick case on a sunny desk. If your phone runs hot on a wireless pad, try a cable for a week and see if it settles. More detail in is fast charging bad for your battery.
If your iPhone shows a hold message rather than getting hot, our Charging On Hold guide explains what it's doing.
05Habits and gear that keep it cooler
If you can't do without a case, a thin heat-dissipation case is the better choice than a thick rugged one. We wrote up what our heat-dissipation case does and doesn't do. For long gaming sessions on a charger, a clip-on cooler fan helps more than any case. See phone coolers for gaming.
Thin cases that don't trap heat, and a cooler for long gaming sessions.
Questions people ask
Is it normal for my phone to get hot while charging?
Warm is normal, especially with fast or wireless charging. Hot enough that it's uncomfortable to hold is not. Unplug it, take the case off, and let it cool somewhere shaded before charging again.
Can overheating while charging damage my phone?
Repeated high heat ages the battery faster, so it holds less charge over time. Phones protect themselves by slowing or pausing charging, but avoiding heat in the first place keeps the battery healthier for longer.
Should I stop using my phone while it charges?
Light use is fine. Heavy gaming, video calls or navigation on a fast charger makes the most heat, so take a break or switch to a slower charger if it's getting hot.
Is wireless charging hotter than a cable?
Usually, yes. Some energy is lost as heat between the coils, and more if the phone isn't centered. A magnetic charger or stand keeps it aligned, and a cable is the cooler option if heat is a problem.
When is an overheating phone dangerous?
When you see swelling, a bulging screen or back, a chemical smell, hissing or smoke. Stop charging, move it away from anything flammable and have the battery checked. Don't keep using or charging it.