Why you can trust ZDNET : ZDNET independently tests and researches products to bring you our best recommendations and advice. When you buy through our links, we may earn a commission. Our process

'ZDNET Recommends': What exactly does it mean?

ZDNET's recommendations are based on many hours of testing, research, and comparison shopping. We gather data from the best available sources, including vendor and retailer listings as well as other relevant and independent reviews sites. And we pore over customer reviews to find out what matters to real people who already own and use the products and services we’re assessing.

When you click through from our site to a retailer and buy a product or service, we may earn affiliate commissions. This helps support our work, but does not affect what we cover or how, and it does not affect the price you pay. Neither ZDNET nor the author are compensated for these independent reviews. Indeed, we follow strict guidelines that ensure our editorial content is never influenced by advertisers.

ZDNET's editorial team writes on behalf of you, our reader. Our goal is to deliver the most accurate information and the most knowledgeable advice possible in order to help you make smarter buying decisions on tech gear and a wide array of products and services. Our editors thoroughly review and fact-check every article to ensure that our content meets the highest standards. If we have made an error or published misleading information, we will correct or clarify the article. If you see inaccuracies in our content, please report the mistake via this form.


So, how exactly do you tell how hot your iPhone is?

It turns out it's difficult. Needlessly difficult.
Written by Adrian Kingsley-Hughes, Senior Contributing Editor
NurPhoto / Getty

Yesterday, I wrote about how heatwave temperatures can damage -- even permanently damage -- your iPhone's battery. And even if your iPhone escapes damage, it can put your phone into a mode where you can't do much with it until it cools down.

Then I get what an obvious question is, but one I hoped you wouldn't ask.

How do you tell how hot your iPhone is?

You could wait until your iPhone throws up the high-temperature warning, and then, well, you know it's too hot.

That's the only mechanism that Apple offers.

But surely, the iPhone has a built-in temperature sensor, and there must be apps that can read and display that data.

Surely there's an app for that.

Well, I found one, but I had to download and test dozens of apps in order to find one that will display a reading from the temperature sensor.

The one I found is called Battery and charger test, and while this app looks rather simplistic and does display ads (some especially annoying), it also display a temperature, and this seems to be reasonably accurate. I checked the temperature of the iPhone using a thermal camera, and also warmed and cooled the iPhone to monitor temperature changes. 

It seems reasonably accurate, and right now the best we seem to have.

Battery Charge and Test app showing internal sensor temperature

Battery Charge and Test app showing internal sensor temperature

I dug through a few dozen more apps after testing the Battery and charger test, but I couldn't find anything. If you know of another app that gives temperature readings, let me know.

Don't want to bother with an app? I can think of two other methods:

It's a shame Apple doesn't offer up this information, as it could be something that could help users get more life from their battery.

Editorial standards