For an example, old 11 Pro Max (iOS v17.6.1) got so hot that its screen got darker like my hot 12 mini, Maps app couldn’t display and talk anymore (this was new during the road trip), etc. Its iOS notification said iPhone was too hot. :( Do newer iPhones (e.g., 15) have this problem too?
Thank you for reading and hopefully answering.
I’ve not had that problem with any of my iPhones.
I’ve noticed that my iPhone 13 mini gets very warm (often too warm to charge the battery) much more frequently than in the past. I am pretty sure the problem started after moving to iOS 17, though that may not be the actual cause of the issue. As a phone ages, I’d normally suspect the battery first, but battery health is good on my phone.
I have found this to be true as the phone ages. Whether it’s a battery issue or the iOS is too much for the phone, I don’t know. My battery health is down in the 80s (13 Mini)
Diane
I’d have that battery replaced if it was mine. My 11 Pro doesn’t have this issue.
There’s separate issues at play here.
One is the well documented overheating issue on 15 Pros. Apple provided a “fix” early on through an iOS update, but ever since some folks have still been complaining about overheating Pros, especially when taking photos or movies. Lots of those complaints center around people not being able to snap the pic at the exact right moment because of lag due to overheating in the middle of a more extended shoot session.
The other is a problem that has plagued all iPhones since at least the 12. Their OLED screens dissipate a lot of heat when cranked up to high brightness. Now if you happen to live in Kautokeino, that’s likely not a problem because you rarely see the sun anyway, but for those of us living in areas with lots of sunshine and warm temperatures (like, incidentally, where iPhone’s developed — so how’s that for irony?) this can become a real issue. When it’s very bright outside, the screen cranks up its brightness and the iPhone gets very warm. Unfortunately, when it’s that sunny and bright in these locations, it’s also often quite warm (or really hot for those fortunate enough to live in the Sun Belt) and so then the iPhone overheats which leads to iOS dimming the screen in a drastic attempt to lower device temp (keep in mind this is critical because high heat will eventually kill a Li-ion battery) without actually suspending iOS. This is very unfortunate because it means at exactly the time when you’d need the bright screen the most, is when you’re getting the darkest screen. It’s a real bummer. But I guess, bar better screens (the actual solution), it’s still better than having the iPhone suspend itself entirely just to cool off. Either way, defeats the purpose of a brighter screen. And I’d much rather see Apple develop an actual solution for this conundrum than fuzz around with yet another life-changing universe-altering we-think-you’re-going-to-love-it button or for the umpteenth time changing the hue of one of their case colors by 0.3%. /hint
The only thing you can do about the former is take fewer pictures and videos or take them only from within a freezer. The only thing you can do about the latter is either move to a place where the sun never shines (London, Copenhagen, Malmo, or Seattle are all great candidates and actually really nice cities, if you don’t mind never seeing blue skies) or you just stop using the iPhone outside. Joking aside, it’s really not something for which a user-side fix exists. You can moderate your use under certain cirumstances, but of course that kind if negates the purpose. For people experiencing this problem in car mounts, good practice is to make sure the mount is in front of a vent. The constant flow of cooler air from the car’s vents will cool the phone down. That can be very helpful, since navigating with Maps tends to use a lot of CPU cycles and relies on cell data which means (especially out in the boonies) radio circuitry is also fired up so the iPhone tends to otherwise heat up quite a bit. But blast it with AC and you’ll most likely be just peachy. 
I really hope Apple make improvements in tomorrow’s 16 and on. Heck, even using iPhones indoor can get hot!
Does it keep doing this even after you restart? Sometimes background processes can get out of control and use a lot of power.
A poor cellular connection can also be a source of increased heat. It’s trying harder to lock onto the signal.
Yeah, in Yellowstone Park with lots of no and weak signals. I guess use Airplane mode to turn off cellular fully to help?
Simon, thanks for this detailed explanation. I have been alarmed several times at how hot my iPhone got when using it for CarPlay. Battery was not an issue because it was attached and powered by USBC, but I knew high heat was very bad in general. I have tried to keep it out of sunlight, but driving around town that is hard to do because the angle of incoming light varies. Based on your discussion, in the future I will try to lay it on the seat with the screen down. That should turn off the screen which will help some.
You can turn off just cellular on iPhone if this is an issue for you.
The only times lately when I’ve noticed my iPhone 11 getting hot are:
If it persists I restart the iPhone, and there we are.
I like your reference.
Since I live in a place where this year it feels like it never stops raining, I have the opposite problem. My car mount is in front of the vent and the warm air makes the phone too hot. Never happens in any other situation, so confirming what you write about
in a backwards way
And some of us have both problems.
In Virginia, we get hot summers and cold winters (well, not as cold as upstate New York, but cold enough).
In the winter or at night, I use a sticky pad to keep my phone on the dash. In the summer, I use a vent mount to keep it in front of the cold air from the A/C.
Sometimes, when traveling and a renal car doesn’t have a good place for the sticky pad, I’m forced to use the vent mount in the winter. In this situation, I simply close that vent (most cars have a way to do that) to keep the hot air away from the phone. That’s usually good enough.
Cold in Virginia? Kautokeino is in northern Norway.
Oh I hate those. Always on the lookout for a rest stop.
Don’t get me wrong, Kautokeino is a magnificent place with wonderful people. If you feel that the rampant manhattanization of Tromsø or Harstad has gotten out of hand, then Kautokeino is your place. 
I just wouldn’t go there for the weather. 
When in winter I have the heater running (yes, those drastic Bay Area winters! of course not quite as dire as in Virginia but still), I just close off the vent behind the iPhone mount. Never had a problem with that setup. Although I have to admit that vent design is garbage because even with the vent closed I can still feel some warm air coming out of there. But hey, 10 year old car at 100k miles that still gets 50 miles to the gallon so as long as that vent is my only issue I’m a happy camper.
Tee hee!
Good advice from all.
But, um, er how about not using your phones so much? Paper maps, maybe?
Ah, a new marketing opportunity! A leather holster with crafty receptacle for liquid nitrogen to keep your iPhone in tip top shape! (Manufacturer caution: avoid prolonged contact between thigh and holster.)
Dave
Anything you can do to reduce power consumption should reduce heat as well as extending battery life, so follow the usual battery-saving techniques. Switching to Low Power mode will reduce background processing and network activity. I’m also a big fan of using the more power-efficient 4G as opposed to 5G (especially since my old 12 mini has a less-efficient 5G modem than some of the newer phones.)
In the past, I noticed Apple Maps was more power efficient than Google Maps or Waze. I think the Google apps are better about this now, but still a bit behind Apple’s.