Phone Overheating in a Hot Car: What to Do

Why cars are so hard on phones

A parked car in the sun heats up quickly, and a phone left on the seat or dashboard soaks up that heat. Apple, for example, designs iPhones to work in ambient temperatures between 0 and 35°C. On a sunny summer afternoon in Ontario, the inside of a closed car can climb well past that.

Driving can be just as tough. Picture a phone on a windshield mount in full sun, running turn-by-turn navigation with the screen at full brightness, streaming music, holding a cellular connection and charging at the same time. Every one of those adds heat, and the phone has nowhere to shed it.

Signs your phone is too hot

• A temperature warning appears and the phone limits what you can do until it cools.
• The screen dims on its own, even with brightness turned up.
• Charging slows down or pauses.
• Apps lag, the camera flash is unavailable or navigation stutters.
• The phone feels uncomfortably hot to hold, especially near the cameras.

These are protective features. Your phone is cutting back to keep itself and its battery from getting hotter. Treat them as a signal to act, not something to work around.

What to do right now

1. Stay safe first. If you're driving, pull over somewhere safe or let a passenger handle the phone. Don't fiddle with it at highway speed.
2. Unplug it. Disconnect the charging cable or take it off the wireless charging pad. Charging adds heat.
3. Take off the case. Thick or rugged cases hold heat against the phone.
4. Get it out of the sun. Move it into shade, under a seat away from the window, or into an air-conditioned space.
5. Close the heavy apps. Quit navigation, video and games. If you can manage without it for a bit, turn the phone off.
6. Let it cool gradually. Give it time at normal room temperature before you start using it hard again.

What not to do

• No freezer, fridge or ice packs. A sudden drop in temperature can cause condensation inside the phone, and that moisture can do its own damage.
• No cold water. Even water-resistant phones shouldn't be dunked to cool off.
• Don't keep charging it. Plugging a hot phone back in before it cools only adds more heat.
• Don't ignore a swollen battery. If the screen is lifting, the back is bulging or there's a new gap along the edge, stop using it, don't charge it and don't press on it.

Smarter habits for summer driving

Rethink your mount

A dashboard or windshield mount in direct sunlight is the hottest place in the car. A vent mount with the air conditioning running keeps the phone in moving air instead. If your vent mount sits in front of the heat in winter, switch vents when the seasons change.

Charge before you leave

Top up at home rather than fast charging on the dash while navigating. If you need to charge on a long drive, a cable usually runs cooler than a wireless car pad, and you can unplug once you have enough charge.

Download maps ahead of time

Offline maps in apps like Google Maps and Apple Maps mean less data use while you drive, which takes a little load off the phone.

Never leave it in a parked car

Take your phone with you, even for a quick stop. The glovebox and centre console still get very hot. The same goes for tablets, laptops and game consoles on a road trip.

How heat damages your battery over time

Lithium-ion batteries age faster when they're hot, and the damage is permanent. One overheating episode usually won't ruin a phone, but repeated heat over a summer can leave you with a battery that drains quicker, shuts down unexpectedly or reports lower health in your battery settings. In worse cases, heat contributes to swelling.

If your phone hasn't been the same since a hot spell, our phone battery guide explains how to check battery health and what the readings mean. A worn battery can usually be replaced without replacing the whole phone.

When to call a technician

If your phone keeps overheating in normal use, won't hold a charge after a hot day, or shows any sign of swelling, it's time to have it looked at. Our battery replacement service comes to you: a certified woman technician visits your home, workplace or parked car across our service area. You'll get a free quote before any work starts, and she'll test the phone with you when it's done. Call or WhatsApp (365) 351-4247 or book online.

Frequently asked questions

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