I live in the Western US (southern part of California) and this time of year can be brutally hot. We've been running in the range of 95F to 105F (35-40C) consistently over the past month, with some days even hotter. On the extreme end, there was a group of German motorcycle riders in Death Valley last month, and one died due to heat exposure.
I like MRA Next for navigation, but what can I do to operate my phone safely when exposed to this kind of external environment? Phones don't like heat in general. Add the processing load from the navigation app while keeping the phone plugged in only makes things worse. I guess the easy answer is to wait until it gets cooler, but not taking trips for 3-4 months isn't a very attractive option.
Any hints or tricks would be appreciated.
@John-S-Parry
I understand your problem. I live in The Netherlands and we can have temperatures in the range of 30°-35° C. And we also experience issues with smartphones with this heat.
What can you do?
Best advice: keep your mobile out of the heat! It sounds stupid and corny, but it is a fact.
Other advice, if you use your mobile phone on your motorbike, place it in such way in a phone holder that it will be cooled by the wind when you're driving.
You're using it in a car? same advice, place your mobile phone in a shady place. Don't place it in a holder attached to your car front window directly in the sun. Maybe you can use a phone holder with clips and attach it to the air outlet grille on your dashboard. The flow of air comming from the airconditioner might keep your phone cool.
That's basically the only advice: keep your phone out of the heat! Again, it's a cheap, corny, stupid advice but it's a fact.
Use an outdoor phone, they can handle heat better. Or an Carplay / Android Auto Display, with that your phone can stay in your pocket.
@John-S-Parry said in Dealing with Heat:
one died due to heat exposure
That's a sad thing. 
Hardware
iPhone 12 pro (iOS 17.0.2)
Oukitel RT3 (Andr. 12)
Samsung Galaxy XCover 4 (Andr. 9 Pie)
Wireless CarPlay mit (Elebest C650)
Wired CarPlay (SEAT Arona - 2021)
For more information, click here
@John-S-Parry known issue to MRA development team, where the app uses excess battery consumption, then combined with the heat to charge + ambient, well, the app is useless.
I live in Texas and have fought this issue since inception, and until the issue is solved/rectified, unfortunately, MRA app is on the shelf.
Thanks. I've tried all the obvious workarounds. I was hoping that maybe there would be something I've overlooked.
Last week, on 3 separate rides I got the iPhone message "charging on hold due to high battery temperature". This was with the phone inside my tank bag, and the bag partially unzipped to allow airflow. Not charging would certainly help, but the app is power hungry, and I wouldn't be able to ride long without needing a charge.
At least for the hot months, I'll go back to navigating using my Zumo XT with MRA routes created on my PC. The XT doesn't care about heat and will run through just about anything. I want to see the route while riding anyway, and I don't see another solution.
@Jörgen The phone still has to do all/most of the work when used with CarPlay, even though the display is off. It will get quite hot in your pocket.
@John-S-Parry unfortunately, I am 100% in the same boat....long trips, I use the XT (works great), and shorter ones, Google/Apple Maps or Scenic. This issue has been ongoing for over a year now, and apparently resides on the HERE side. So discouraged that it is still out there, however, all one can do is cross your fingers and hope.....
@Herko-ter-Horst I can not agree to this, my iPhone is not getting hot.
Anyway, I manly use an outdoor Tablet (Oukitel RT3). And I had no issues at 35° degree. In navigation mode.
@GT-JWR said in Dealing with Heat:
the app is useless.
A nice comment, but not true. It may be not working for you, but not useless for me.
Try dark mode.
Keeping the screen lit on a modern phone (i.e. OLED display = iPhone X and newer) takes a lot of power, and also increases heat generation.
Minimising the number of pixels being lit decreases battery usage and associated heat generation.
Battery savings are estimated at ~14-60% with dark mode. Heat isn't usually discussed in battery-saving articles, but you can be sure that less battery usage = less heat, especially if the screen is auto-brightening to overcome sunlight/bright ambient light, and the screen is permanently on as it is with satnav apps.
Whether it's enough to save you, only you can find out.
Good luck!
@John-S-Parry Chuck a cool pack from the freezer into your tank bag to keep the phone cool? I'm from rainy cool Northern Ireland and in July 2008 I took my kids to Disney in Florida. 30+ Centigrade of heat and humidity did not sit well with this pasty Irish man. So I got a 2litre camelbak from Walmart and filled it every night before a park visit and put it in the freezer. I slung it on when I got to the park and sipped at the melting water. The cooling effect lasted about 3-4 hrs. I needed a small towel between my T-shirt and the Camelbak for the first hour or so to avoid freezer burn 
@John-S-Parry I would suggest using a dedicated CarPlay unit like the Carpuride or Chigoe units, you can then leave your phone away out of the sun in a shaded place and use MRA for your navigation via CarPlay.
Thanks for the additional suggestions. I did try dark mode, but it made the screen difficult to view when the sun is high. And with the phone stored inside the tank bag, the phone screen goes to sleep anyway. The cool pack from the freezer might have some merit. The effect won't last for more than a few hours, but it might be worth exploring.
In fairness to MRA, the problem is more with running full function GPS apps on phones in general. It's simply a resource intense function that that phones are not directly designed for. I run another navigation phone app based on Apple Maps that has some of the same heat generation issues. It doesn't happen as quickly as on MRA Next w/HERE, but ultimately it's not an all-day app in hot weather conditions. That's why I question if tweaks to HERE will make a revolutionary difference.
For me, going to a Tablet or an outdoor phone as a dedicated navigation device isn't a solution. I already have the Zumo XT for that purpose. For me, the promise of MRA Next is that it's on my everyday phone. I like that convenience.
I'll continue with experimenting with different phone settings to see if anything makes a noticeable difference. Thanks.
@Frappawotsit The problem is that my phone is already out of the sun, and the battery still overheats to the point where phone charging stops. That's not a phone safe condition to experience often. For a hot climate, I don't see CarPlay providing heat solutions.
I can be quite simple about this.
It’s an issue, no doubt.
HERE has confirmed it.
Do they know how to fix it? No!
Am I annoying them and helping to get to a solution? Yes!
Some users experience issues, others not.
Some devices get hot, others not.
Only realistic suggestions are to limit usage other apps, enable battery saving, lower brightness if possible and keep phone in a stable environment.
Yes, I ride motorcycle, no the suggestions are not always realistic.
I drive with battery saving on, limited apps open and have no issues with battery usage. But as said, that’s not the same for all 
@John-S-Parry I use my XT a lot as well......but for completely different reasons. Today 17C/63F and chucking it down with rain.....no wonder Ireland is green!! 
@Mzokk My wife and I did a British Isles cruise last year and had a blast. Your part of the world is beautiful -- and green! It's a much different landscape than the constant brown we have in much of the sun baked Western US.
I'm a huge fan of the MRA Routeplanner. I'm a competent Basecamp user, so I was reluctant to initially give Routeplanner a try. I soon found it was an exceptional product, and I've almost completely converted to it. I understand that MRA Next is even a bigger nut to crack. Given the range of phones and environments to take into consideration, the product is an incredible achievement. BUT, I believe the demands of the navigation SW in many cases exceed the processing boundaries of phone HW. Next is a good product. Hopefully, the SW/HW will work in harmony in all environments that a Garmin GPS successfully operates in.
@Corjan-Meijerink I haven't tried "low Power Mode" on my iPhone yet. Thanks for the suggestion. Maybe it will make a meaningful difference.
@richtea999
On Oled dark mode can save energy. That is true but with Android Auto or Apple Carplay, you do not use the screen at all and it can be switched off. But even in this situation there are a lot of people who encounters heat issues.
Because of this. Keep your phone in a cool spot, like in the wind. Is the best you can do right now
(I use MRA Next only on Android Auto. Every comment, suggestion, etc will be based on my usage with Android Auto)
Maybe there's a niche market for phone heatsinks?
Oh, it's called 'gamers':
https://www.amazon.co.uk/s?k=phone+cooler
Obviously no good for a motorcyclist's jacket pocket, but I guess they might be useful in cars and other airy situations.
Some even have decent stars/reviews:
https://www.amazon.co.uk/Black-Shark-Magnetic-Cooler-Semiconductor/dp/B09CGTLDB7/ref=sr_1_9
I've tried a cooler like that. Didn't help much. If you have your phone in a pocket of tankbag. The small area around the phone becomes warm also. So where to dissipate the heat?
A cooler will only work if it can rid of the heat.
@M-Schrijver said in Dealing with Heat:
@richtea999
On Oled dark mode can save energy. That is true but with Android Auto or Apple Carplay, you do not use the screen at all and it can be switched off. But even in this situation there are a lot of people who encounters heat issues.
Because of this. Keep your phone in a cool spot, like in the wind. Is the best you can do right now
True statement. If I'm riding my bike in 90F+ (32C+) temperatures, while running any phone navigation app, bad things can start to happen on my iPhone. Certainly with the phone mounted and even when stored in my pocket/tankbag.
First, the iPhone will stop battery charging to prevent damage. As the temps rise the phone will try other measures to combat internal temperature. Your screen might dim, and other phone features might temporarily disable. After that as a final defense, the phone will automatically shut itself down.
It's the nature of phone GPS navigation apps for these bad things to potentially happen. You're running a processing/battery intensive app while the phone is likely plugged in. This can generate significant heat by itself. With high external ambient temps thrown in, the total heat can overwhelm the phone.
If there is any good news, I get the impression that much of the MRA user base is in Northern Europe, which in general, does not suffer the constant summer heat levels experienced in much of the US. That's why some report problems, and others don't. For 9 months of the year, I can run Next or any other app without issue. It's dealing with the summer months that's the problem.
@Herko-ter-Horst I can not agree to this, my iPhone is not getting hot.
Anyway, I manly use an outdoor Tablet (Oukitel RT3). And I had no issues at 35° degree. In navigation mode.
@GT-JWR said in Dealing with Heat:
the app is useless.
A nice comment, but not true. It may be not working for you, but not useless for me.
