Why Is My Phone Overheating? How to Cool It Down Safely

We're writing this in the hottest week of the year so far, and I've lost count of the phones that have come across the bench too warm to hold. Most of them are absolutely fine. A phone that gets hot and switches itself off isn't dying, it's sulking, and it'll get over it. What you do in the next ten minutes is what decides whether it stays fine or ends up needing a new battery.

A hot phone is usually looking after itself

Your phone keeps an eye on its own temperature constantly. When it gets too warm it quietly throttles itself: slower processor, dimmer screen, charging paused. Push it further and it'll throw up a warning and refuse to do anything at all until it's cooled off. None of that is a fault. It's the phone shielding the battery and the chips from heat that would genuinely damage them if it just let things carry on.

Apple reckons 0 to 35°C is the range an iPhone is happy running in, and most Androids aren't far off. We've been sat well above 35 in the shade all week, which, let's be honest, the British aren't built for and neither are our phones. So one left in the sun or worked hard outdoors hits that ceiling in no time. When it does, the best thing you can do is nothing. Leave it be and it'll come good on its own.

What's actually cooking it

It's nearly always two things stacked on top of each other: the weather outside, and whatever the phone is busy doing inside. The usual suspects we hear about over the counter:

• Sun and hot cars. A phone on a dashboard or a sun lounger can be at 50°C before you've finished your ice cream. This is the big one. It'll do more harm to a battery in an afternoon than a year of normal day-to-day charging.
• Charging in the heat. Charging makes its own warmth, so doing it in a hot room or on a wireless pad in this weather is heat piled on heat.
• Games, sat-nav and video. Half an hour of a proper 3D game, or sat-nav blazing away on full brightness in a sunny car, gives the processor a real workout and warms the phone from the inside.
• A chunky case. A big rugged case is basically a tea cosy for your phone. If it's struggling in the heat, slip the case off for a while and let it breathe.

And one that panics people for no reason: a phone that's just updated, or just had a big photo backup kick off, will run warm for a quarter of an hour while it sorts itself out in the background. Totally normal. It settles down by itself.

Cooling it down without wrecking it

If it's hot and grumpy, here's how to bring it back round without doing any harm:

1. Get it out of the sun. Shade, or indoors. Nine times out of ten that's the whole job done.
2. Take the case off so it can breathe.
3. Unplug it if it's on charge. Let it rest instead of making it work.
4. Quit whatever's hammering it, the game or the sat-nav. Sticking it on Aeroplane mode for a minute helps as well, because the phone stops hunting for signal.
5. Then leave it alone for five or ten minutes.

That last one is the secret, and it's the one nobody wants to hear. No clever trick, no app off the store, just a bit of patience while it cools.

Whatever you do, keep it away from the fridge

Do not put a hot phone in the fridge or freezer, and please don't hold it under the cold tap. We see the aftermath of this every single summer. Cool a phone down too fast and it draws warm, damp air inside as it shrinks, and that moisture condenses on the circuit board, the same way a cold can of pop sweats on a hot day. You can take a phone that was only a bit warm and hand it a proper water-damage fault, which is a far bigger and pricier headache than the one you started with. If you've already done it, don't panic, our water damage guide talks you through the first minute. But honestly, just cool the thing slowly in normal air and you'll never need it.

That "needs to cool down" screen

Every so often an iPhone throws up a black screen with a little thermometer and the line "iPhone needs to cool down before you can use it." Android does its own version. We get these carried in as full-blown emergencies, and nearly every time there's nothing wrong with it. The phone has simply put itself in timeout. Somewhere cool, ten minutes, and it starts up like nothing happened. And if you're ever worried, you can still ring 999 even while that screen's showing.

When it's actually a fault, not just the weather

This is the part where it's worth a proper look. Weather heat disappears the moment the phone cools down. A fault doesn't go anywhere. Get it checked if any of this sounds familiar:

• It's hot doing nothing. Warm on the side, screen off, in a cool room? Something's working away in the background that shouldn't be, usually a dodgy app or a battery that's on its last legs.
• The back's bulging, or the screen's lifting at one corner. That's a swollen battery prising the phone apart, and it gives off heat while it does it. Stop charging it and bring it in. A swollen lithium battery is the one genuine safety risk in all of this, so it's not one to sit on.
• It only cooks on charge. A worn-out charging port, a cheap cable, or a bargain-bin battery fitted somewhere down the line will all do this. We swap out a lot of cheap third-party batteries that run hot and die young. A proper one puts it right.
• It's hot and the battery's vanishing as fast as it heats up. Those two together usually mean the battery's had it. We change more than thirty a month, and there's more on spotting a tired one in our battery care guide.

If it's an iPhone, our iPhone repair page covers batteries and charging ports. A Galaxy or another Android, that's Samsung and Android repair. Either way it's usually a same-day job, often done before you've had your coffee up the road.

Surviving the heatwave with your battery intact

A few habits that'll keep you out of our shop (no offence taken):

• Never leave your phone on the dashboard or a sunny windowsill.
• Charge in the evening in a cool room, not in a roasting car on the way out somewhere.
• Knock the brightness down, or let it go automatic. A screen on full blast in the sun is a heat source in its own right.
• Case off if you're charging on a hot day, or running sat-nav for a long drive.
• The rule we give people at the counter: if it's too warm to hold against your ear, it's too warm to be using. Give it a rest.

When to bring it in

If your phone only gets hot in the sun, in the car or mid-game and perks back up once it's cooled, you don't need us. Just keep it out of the heat. But if it's hot while doing nothing, the back's started to swell, or it only overheats on charge, get it looked at before it grows into a bigger bill. You'll find us at 5 The Fairings, right in the middle of Tenterden, opposite the Waitrose car park. Pop in during shop hours, or book a slot online. Coming from a bit further afield? Have a look at the areas we serve page for drive times.