My phone threw a temperature warning while navigating. What should I do?

Stop navigating, take the case off, and move the phone somewhere shaded or near an air-conditioning vent so it can cool naturally. Wait for the warning to clear before continuing. Do not put it in a fridge or press a cold pack against it — condensation is a bigger risk than the heat. On long summer drives, let the phone rest every couple of hours.

Why does wireless charging overheat so easily in the car?

It is the fullest version of the five-source stack: wireless charging loses more energy as heat, and that sits on top of GPS, an always-on screen, cellular data and sunlight through the windshield. Switching to a cable and moving the mount out of direct sun makes a noticeable difference.

Does navigation heat damage the battery?

Not in the short term — the system dims the screen and pauses charging to protect itself. The real cost is that repeated high temperatures accelerate battery aging. If you navigate and charge in a hot car every summer day, it is worth checking Settings → Battery → Battery Health & Charging once a month.

iPhone Hot While Navigating? Five Heat Sources Stacking in a Car

The short answer: a phone that gets hot while navigating is five heat sources stacking at once, and it is the most common overheating scenario in daily use. The screen stays on for the whole trip, GPS keeps solving your position, cellular data keeps streaming, plenty of people charge in the car at the same time, and in summer there is sunlight through the windshield. None of those is fatal on its own. Together they can push the body into thermal protection. Warm is fine. A screen that dims by itself and charging that stops are the system protecting itself — not a fault.

The five heat sources, one at a time

The screen stays on. Navigation keeps the display lit for the entire trip, and the screen is the second-biggest heat source in any iPhone — see Why the screen drains battery and generates heat.
GPS runs continuously. The positioning chip and the processor keep solving your location in real time, for hours.
Cellular data keeps streaming. Live traffic and online maps mean a constant data connection, and at highway speed the phone hands off between cell towers repeatedly — which costs more power than sitting still.
You charge in the car. Charging generates heat on its own, and wireless charging is less efficient and therefore hotter; the mechanism is in Wireless charging heat.
The sun. In summer a dash-mounted phone under the windshield absorbs more heat from sunlight than it produces itself. Apple's recommended operating range is 0–35°C (32–95°F), and the inside of a car in the sun is far outside it — how to judge this is in What temperature is too hot?.

What dimming and paused charging mean while navigating

These are the two most misread signals. The screen dims suddenly — even with auto-brightness switched off — because the system is cutting the output of the screen, which is a heat source. Charging stops at some percentage and will not move because the system has paused charging, another heat source. Both are standard thermal-protection actions, and both reverse on their own once the temperature drops. The full mechanism is in Screen dims, charging paused: how thermal protection works — that article sits under the iOS 27 pillar, but the protection it describes is not version-specific.

One thing that does not help: closing apps, restarting the phone, or reinstalling the maps app. The limit is deliberate, and no software gesture lifts it while the body is still hot.

What you can do right now

Move the mount out of direct sunlight. The centre of the dashboard is the worst spot. Shade, or a vent-adjacent mount, gets it out of the sun and improves airflow — the point is dodging sunlight, not blowing cold air onto it.
Use a cable instead of the car's wireless pad. Wireless charging plus navigation is the hottest combination available.
Download offline maps. Grab the regions you use often before you leave; the cellular stream — one entire heat source — drops sharply.
Do not run brightness at maximum. Auto-brightness, or a manual mid setting, takes load off the screen immediately.
Take the thick case off. Especially anything with metal in it.
On long drives, break every couple of hours. Let the phone rest too.

Where this article stops

Three neighbours get mixed into navigation heat. If the problem is charging slowly or not at all, the troubleshooting order is in iPhone charging slowly or not charging. If the question is whether charging while using the phone hurts the battery, see Does charging while using damage the battery?. If the heat started in the days after a system update, see iPhone overheating after an iOS 27 update. This article covers the navigation scenario itself. And if the phone is already too hot to hold and you want to act now, see iPhone hot to the touch.

When is it actually abnormal?

Hot to the touch in the shade, not charging, not navigating: navigation is not the cause — troubleshoot idle heat instead;
A temperature warning on every single trip: the usage pattern is living above the limit; change the habits above first;
Repeated high temperatures over months: the cost is accelerated battery aging. Check Settings → Battery → Battery Health & Charging monthly, and see What is battery health?.