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How hot is your Android smartphone?

Naturally, when you're equipped with a thermal imaging camera, you want to point it at all the things. The FLIR One Pro thermal imaging camera is certainly fun to play with, even though its battery life is finicky. I rounded up a couple of the latest Android-powered smartphones I had laying around, including the LG G6, Galaxy S8, and Pixel XL, to see how hot they become (if at all) when they're plugged in and running a benchmark. Why the heck not?

Note: I'm using a version of the FLIR One Pro thermal camera that's running on beta software.

As they lay charging

The temperatures of the Galaxy S8 (left), LG G6 (middle), and Pixel XL (right) as they're charging with the screens on at high brightness.

It took a while for the FLIR One Pro to charge up enough to shoot the three smartphones. I pointed the One Pro at a Galaxy S8 as it charged through a USB-C cable connected to an Aukey power strip. It measured in at about 89 degrees Fahrenheit. The LG G6 measured in around 84 degrees. Both had their screens set on to full brightness.

The Pixel XL measured in surprisingly warmer at nearly 94 degrees. It was charging from the same power strip, with the screen brightness on full blast. The FLIR One Pro simply reinforces what I've been thinking for the past eight months: the Pixel XL runs hot.

While they're benchmarking

Have you ever seen how hot a smartphone becomes when it's plugged in, throttling, and running a graphics-intense benchmark at the same time? That's what the FLIR One Pro can show you. In this case, we have a very warm set of phones, all of which are running the 3DMark benchmark suite while charging from the same power strip.

The G6 and Galaxy S8 benchmarking, side-by-side.

Here's the Pixel XL benchmarking (left), as well as the Pixel XL running Snapchat (right).

Of course, we can't overlook the fact that there are two different processors at play here. The Pixel XL and LG G6 are both running on a Snapdragon 821 processor, while the Galaxy S8 is powered by a Snapdragon 835. Both processors have different GPUs, too, though none of that seemed to really affect the temperature of either device while it was powering through 3DMark and filling up on battery. In fact, the overall heat output of each phone seem to correlate more with the brightness of each screen. For instance, perhaps the G6 measured the lowest because its screen was the dimmest of the three.

What about a smartwatch?

What about a smartwatch? Unfortunately, it was not a warm-enough day for me to show how truly heated an Android Wear watch like the LG Watch Style gets — or at least, seems to get, based on my own anecdotal experience — but it sure is dormant when it's not being bombarded with app notifications. Interestingly, when it's charging, it measures in at about the same temperature as the Pixel XL.

The LG Watch Style, in thermal mode.

Where else should we feel the heat?

Got ideas about what we should shoot for next?

Got ideas about what we should shoot for next?

Not only is thermal imaging such great fun, but we're also still in the midst of testing out the FLIR One Pro. We're planning to shoot plenty more gadgets with it. Perhaps a networking module like Google Wi-Fi, or the NEST camera while it's on? We're taking requests!

Florence Ion is an editor and columnist at Android Central. She writes about Android-powered devices of all types and explores their usefulness in her everyday life. You can follow her on Twitter or watch her Tuesday nights on All About Android.

19 Comments
  • Part of my home screen Zooper Widget is the phone's internal temperature. Not sure how accurate it is but at least I have some idea. My phone sits in a vent mount in the car so I can put the AC on it when running Waze on a hot day.
  • This is the only time my S8+ gets on. Running waze, plugged in, in the sun during summer. Ooo buddy does that phone get hot. But I do try to point the vent at it.
  • My Moto Nexus 6, according to Battery Widget Reborn, says when playing Age of Empires: Castle Siege my phone temperature hit 107.4 I could feel it getting hot in my hand. I only play in little spurts now.
    I don't know how accurate the reading from the app is, but I notice it while playing. That's not while charging.
  • My Nexus 6 also getting extremely hot when playing Oddworld Stranger's Wrath, I can barely hold it. When it is charging too, if i'm using it at the same time it gets hot.
  • Especially playing and charging at the same time.
  • Well, try beating my Moto Z. With the Mophie mod on and on a TurboPower charger, it gets really warm.
  • I have noticed that the pixel is warmer as well...
  • I'm not seeing any photos on the app.
  • Hit the little browser button on the top right of the ac app. This ac app is hands down the best Android new app available. I've had the AC widget on my second screen since the HTC Evo 4g. Also.. for some reason VR Heads took their app down from play store, so I got the apk from googling it. I keep the VR Heads widget on the 3rd screen on all of my devices. Why did VR Heads get rid of the app? Great app and site with Russel and his crew.
  • My LG V10 with its Snapdragon 808 regularly gets hot just by using it for web browsing. On a warm Missouri day it can get up to 120 degrees Fahrenheit.
  • Fahrenheit. How quaint.
  • Hey I'm up for us switching to the metric system. We'll be one step closer to the Star Trek utopia then. Haha!
  • What amperage or wattage output was each charger rated at? To have these temperature comparisons be worth anything, all phones should be charged with identical wattage.
  • Do the one plua 3/3T while it's charging. Since dash charge promises to not heat up the device, would love to see the proof of that.
  • You should test a phone while charging wirelessly.
  • Note 7!
  • First, can we get measurements in both Celsius and Fahrenheit? My Ampere power meter runs in Celsius, so let's just report both. Also, my Pixel XL is definitely running MUCH hotter today, than when I first got it in November. I'd like to see a comparison using the same phone, but one being fresh out of the box and other after 6 months of use.
  • I'd love to see a comparison of the chargers themselves. Some of those wall warts get pretty damn toasty.
  • People