Pop Stop people are now becoming aware of two iPhone pop-ups that must never be ignored if they want to avoid a large bill.
They might spare you from an expensive disaster. Ignoring either of them could result in severe harm and permanently reduce the battery life of your iPhone.
The first warning screen you need to look out for is Charging on Hold. It's a pop-up message that appears on your Lock Screen.
And it will also appear in Settings > Battery.
The note reads: "Charging On Hold. Charging will resume when iPhone returns to normal temperature." You'll only be able to start charging again once your iPhone has cooled down.
That means moving it somewhere cooler or putting it to sleep, Apple said.
The second pop-up that could appear blocks almost all iPhone usage. It will black out your screen and show a thermometer icon.
The text will read: "Temperature: iPhone needs to cool down before you can use it."
An Emergency button at the bottom will let you use the device for an emergency call in a serious situation.
But otherwise, you'll need to simply stop using your iPhone and put it somewhere cool.
Importantly, it should be out of direct sunlight.
In either pop-up situation, it means your iPhone has become too warm.
This can be very bad news for your iPhone, and its battery in particular.
When an iPhone gets too cold, battery life shortens but will eventually restore once it's back to a normal temperature.
But when an iPhone gets too hot, the battery can be damaged forever.
"Using an iOS or iPadOS device in very hot conditions can permanently shorten battery life," Apple warned.
"Use iOS and iPadOS devices where the ambient temperature is between 0º and 35º C (32º to 95º F)."
If your battery becomes significantly damaged, you may find that it holds much less charge than you'd like.