A temperature warning on an iPhone that feels cool usually isn't about heat. Since iOS 27, owners of iPhone 15 models, and some iPhone 14s, report the full-screen warning on phones that are cold to the touch, which points at the software.
Turn the phone off for fifteen minutes first, then install any iOS update. If the warning started before iOS 27, or survives the updates, the phone's sensors or battery need a technician.
In this guide
What the warning screen means
The screen is a protection state, not a crash. Apple's guide for an iPhone that gets too hot or too cold says a phone showing this message might still be able to make emergency calls, so the phone is running and has locked its own screen.
That's why pressing buttons over and over achieves nothing. The phone isn't frozen. It's waiting for its own temperature reading to drop.
1. Turn it off for fifteen minutes, and time it
Even when the phone feels cool, do this once properly, so you can rule heat out. Power it off completely (not just lock it), move it somewhere cool and shaded, and leave it for a full fifteen minutes before switching it back on.
If the warning stays away, something was warming it from the inside: a case, a wireless charger or an app working hard. If it comes back within minutes on a phone that's still cool, heat isn't the cause, and the next steps apply.
Can't reach the power-off slider? Force restart once: press and release Volume Up, then Volume Down, then keep your thumb on the side button. Release it as the Apple logo comes up, then power off for the fifteen minutes.
2. Warnings that began with iOS 27: update and report
Owners on Apple's forums describe the full-screen warning on cold iPhone 15 and 15 Pro models right after the iOS 27 update. The screen often stutters at a low refresh rate for a few seconds first.
Several say it never happened on iOS 26.
One owner who went back to iOS 26 during the beta found the phone fine there, and the warning returned with iOS 27. In October, owners were still reporting it on the iOS 27.2 beta, so it hadn't been fixed by then.
Install every iOS 27 update as it arrives, in Settings > General > Software Update, because a software fault needs a software fix.
A phone can also run warmer than usual for a while after a major update, so the first few days aren't a fair test.
Report it to Apple at the same time. Apple Support can run diagnostics on the phone and log the fault against iOS 27, which matters more than a forum post.
3. If you were navigating, the dark screen is normal
The alert can also appear while you're using navigation, and the display turns off, but turn-by-turn directions keep coming as audio.
A phone in a windshield mount, in sunlight, at full brightness with GPS running, is behaving as Apple intended.
Move the mount out of direct sun and away from the defroster vent, and remove the case while it charges in the car. The directions don't stop while the screen is dark.
4. Rule out cold, which triggers it too
The warning gets read as "too hot" every time, but Apple's page covers both directions. Very cold conditions can shorten battery life, stop charging and even switch the phone off.
A phone left in a car overnight in winter hits the bottom of the range, and it feels cold because it is. Let it warm up to room temperature on its own, not on a radiator or in front of a heater.
5. Lower the trigger with four free changes
None of these fixes a faulty sensor, but all of them make the warning less likely while you wait for an update or a repair.
- Take the case off, especially one with a magnet or a battery built in.
- Charge with a cable, not on a wireless pad, which warms the back of the phone.
- Turn the brightness down and switch off Always On Display if your model has it.
- Keep it out of the car, the hottest and coldest place most phones ever go.
If the phone really is warm in your hand, an iPhone that runs hot after an update covers the apps and settings that cause it.
6. Book a repair if it predates iOS 27 or never stops
A phone that showed the warning before iOS 27, or still shows it after the updates, needs a technician. The phone acts on what its internal sensors report, and if a reading is wrong, cooling can't change it.
Mention the battery when you book. A recent battery replacement, or a swollen battery, sits right next to those sensors, and what the Unknown battery label means shows how to check what has been changed in your phone.
Keep your expectations modest. On a long iFixit thread about this exact symptom, the top answer blamed a wrong or faulty battery.
The person who asked found a new battery kept the warning away for only about thirty-six hours, so agree in advance what happens if a battery swap doesn't hold.
What doesn't work
- The fridge or freezer. Moisture forming inside a cold phone can do far more damage than the warning ever will.
- Force restarting again and again. One restart to reach the power button is fine; after that you're interrupting a protection state.
- Reset All Settings. The temperature limit isn't a setting.
- Waiting for hours. If fifteen minutes off in a cool room didn't keep it away, more time won't either.
If nothing works
Ask Apple Support for help, online or at an Apple Store, and say whether the warning started with iOS 27. A phone under warranty or AppleCare should be checked for free, and Apple can test the battery and sensors properly.
If the screen goes dark on iOS 27 with no warning at all, that's a brightness bug with its own fix. On a new iPhone 17e that simply runs warm, the 17e heat page separates normal warmth from real overheating.
Why does my iPhone say it needs to cool down when it's not hot?
The phone acts on what its internal sensors report, not on how it feels in your hand. On iOS 27, owners of iPhone 15 models report the warning on cold phones, which looks like a software fault. Before iOS 27, a cool phone showing it usually pointed at the battery or sensors.
Can I still use my iPhone with the temperature warning on screen?
Not normally. The phone might still be able to make emergency calls, because it has locked its own screen on purpose rather than crashed.
Is it safe to put a hot iPhone in the fridge?
No. Fast cooling makes moisture form inside the phone. Switch it off and leave it in a cool, shaded spot instead, which is what Apple asks for.
The Short Version
- Power off for fifteen minutes in a cool room to rule heat out.
- If the warning won't let you, force restart once, then power off.
- iOS 27 brought false warnings on cold iPhone 15 models, so install every update and report it.
- While navigating, a dark screen is normal and spoken directions continue.
- Cold triggers it too, so let a cold phone warm up on its own.
- A warning from before iOS 27, or one that never stops, needs a battery and sensor check.
- Never use a fridge or freezer.
Checked November 8, 2026.
