Why Is My Phone Hot? Reasons And Easy Fix To Overheating

Have you noticed that your phone is getting hot for no apparent reason? There can be for a variety of causes, but here are the most common factors to an overheating phone:

  • Environment Is Too Hot
  • Apps With High Processing Demand Or Keep The Screen On
  • Charging Phone Too Frequently
  • Transmitting A Lot of Data
  • Background And Unused Apps
  • Outdated, Poorly-Written, Side-Loaded, Hacked Apps
  • Too Much Phone Use
  • Needs Servicing Or Replacement

Each of these reasons for a hot phone has easy fixes.

Woman on couch in front of a fan and open refigerator asking "why is my phone hot? "

Environment Is Too Hot

The ambient temperature where you’re using your device is the most common issue for users.

When you are outside, the sun and air temperature add to the heat already produced by your cell phone, especially during the summer days. This additional heat affects your device usage and may cause it to get hot.

If you sleep with your mobile phone in the bed or under your pillow, this insulates the device and adds your body heat as a factor.

Adjusting the environment around your smartphone is an easy fix.

  1. Position your phone so it isn’t exposed to direct sunlight or other heat sources.
  2. Wait for a cooler environment to do high-demand, screen-on tasks like gaming, streaming, video chatting, and social media.
  3. Adjust your heating and air conditioning in your vehicle
    1. When the heat is on, keep your device away from vents.
    1. When cooling, use a vent-mounted holder. I just bought a nicely designed magnetic holder.
  4. Ditch the case. This is easier said than done, especially if you’re accident-prone.

On the Joe Rogan Experience, Neil deGrasse Tyson talks about why he doesn’t use a phone case. Here’s the segment of that video.

Chances are good that you just watched this video on your mobile device. If that’s the case, your phone just got a little hotter due to the time your screen was on and the processing power required to render or draw the video on the screen.

Apps With High Screen On Time And Processing Demand

Some apps will keep your phone’s display active for a long time.

Some apps use your phone’s processor more than others.

Some apps do both.

Tasks That Keep The Screen On

Your smartphone’s display is simultaneously the largest battery drainer and heat producer. Using apps and performing tasks that keep it illuminated contributes to heat production.

In their paper, Analysis of Power Consumption in a Smartphone, Aaron Carroll and Gernot Heiser from the University of New South Wales documented the power consumption of the various components in average smartphone tasks.

Bar graph showing the smartphone component power use during video playback
Bar graph showing the smartphone component power use during sms text messaging
Bar graph showing the smartphone component power use while web browsing
Bar graph showing the smartphone component power use while emailing

The most straightforward solution is to put your mobile phone into a suspended state (sleep; display off) or even fully power off your device until it cools.

Alternatively, lowering your screen brightness will reduce how hot the device becomes. Notice the power consumption significantly increases as you increase the brightness.

Line graph showing the smartphone power going up as screen brightness level is increased

Modern display OLED displays are very efficient at lower brightness levels or while displaying dark colors. But, this is just part of what heats up a phone.

Tasks Requiring Heavy Processing

Your smartphone has a series of processors working in unison to make this device a fantastic multipurpose tool.

While simple tasks like texting and emailing are light on processing, other apps require high-end processor use, which consumes more power. This level of performance comes at the cost of excess heat produced, increasing the phone’s temperature.

Why Do Headphones Give Me Hot Ear S... x
Why Do Headphones Give Me Hot Ear Syndrome? - Headphone University

The following are the most processor-intensive mobile phone tasks.

  • Gaming – High-end graphics rendering takes a lot of heavy processing using your phone’s battery and producing heat, along with requiring the screen to remain on and active.
  • Video Calling – Like gaming, video chatting for long periods causes the phone to overheat because of its high processing demand and uploading and downloading data.
  • Streaming Video – Watching or streaming video or live streaming to the internet is also a high-demand task similar to video calling.
  • Scrolling Social Media – Social media has moved from simple text into audio, video, and interactive media. These new feed elements are large and require heavier data transmission and local processing.

The fixes are pretty straightforward to combat these heat-producing processes:

  • Switch simple puzzles or other low processing demand casual games.
  • Move your video chat call to an audio-only call over the cellular network (though this is less private than using an encrypted messenger app)
  • Wait to stream video until you’re in a cooler location on WiFi, reducing the drain on your mobile data plan.
  • Fight against the FOMO urge and save social media scrolling until later.

In the aforementioned Carroll and Heiser paper, note the power consumption for a simple cellular audio call. At least smartphones do their primary function with low power consumption and heat production.

Bar graph showing the smartphone component power use during a standard phone call

Charging Phone Too Frequently

Sometimes people think that charging their phone more will maximize their battery life, but this is not the case. Overcharging your battery can partly reduce its lifespan by the excess heat produced.

I wrote about maximizing smartphone battery lifespan and uncovered the best brands here.

If you’re looking to protect your battery as much as possible, try to avoid charging while the device is hot or in a warm environment. In fact, stop charging once the power level is above 80% to reduce the time it’s plugged in and producing additional heat.

Charging multiple times a day is better. The heat produced during charging cycles is allowed to dissipate. People hate to run low on battery, but it’s worth keeping your device cool. Most of us are generally near a place to charge our phones:

  • power outlet
  • vehicle charger
  • spare external battery pack
  • computer with an open USB port

Aim to keep your battery between 80-20% and simply start looking to charge around 40% and take it off the charger if you’re above 80%

There are even apps where you can set up custom notifications. I use BatteryBot Pro (F-Droid | Google Play), which can monitor the power level and your mobile phone’s temperature.

If you’re not near a power source, then it’s a good idea to turn off anything that’s not necessary. It includes WIFI, Bluetooth, and GPS. These services can suck up a lot of battery life and produce heat themselves.

Transmitting A Lot of Data

Transmitting and receiving data is another heat source, albeit to a lesser extent. Cellular, WiFi, and Bluetooth are the three primary radios on modern smartphones. While their power use is not as significant, combined, they can contribute to smartphone temperature increases.

Goran Kalic, Iva Bojic, and Mario Kusek of the University of Zagreb reported a comparison of the battery drain from these three communication radios. Their paper, Energy Consumption in Android Phones when using Wireless Communication Technologies, quantifies and compares the relationships.

Line graph showing smartphone battery consumption percent declined by 3g, wifi, and bluetooth data transmission radios

While Bluetooth is less power-consuming, most users tend to keep all three technologies switched on, leading to additional heat production. For example, you might have multiple Bluetooth headphones that you use throughout the day while coming in an out of WiFi connectivity.

Background location services through a GPS radio and newer, faster cellular radios for 4G and 5G contribute to the internal temperature of modern mobile phones.

Below are a few things to consider if you find your phone is getting hot:

  • Turn off WiFi – Disconnect from your WiFi when not needed. I use WiFi Automatic (F-Droid | Google Play) to automate this.
  • Turn off your Bluetooth – Unless you frequently use wireless headphones, earbuds, or smartwatches, your Bluetooth connectivity is always searching for known devices. I use Greentooth (F-Droid | Google Play) to switch off Bluetooth when the last accessory disconnects.
  • Turn on Airplane mode – If you don’t need to be online or receive phone calls, turn off all your radio transmissions.

Not only does this keep your phone cooler, but it preserves your privacy by preventing WiFi and Bluetooth beacon-based tracking.

Having these radios online is not the main problem. The power consumption and heat production come from when they’re in use. Apps can trigger unnecessary data transmission over WiFi, cellular, and Bluetooth while they’re running in the background.

Close up of smartphone with location sharing causing a the user to ask: why is my phone hot

Background And Unused Apps

Apart from system processes, many apps run in the background of mobile devices.

This happens for location sharing, social media apps, or the latest shopping or travel deal apps. These background operations consume battery using CPU cycles and sometimes audio/visual output even when the application is not front-and-center being actively used.

Mobile operating systems tend to restrict how much processing and data transmission is allowed by background apps. Both an Android phone and iOS device offer a degree of user control regarding how much background activity an app is permitted via settings like “Battery Optimization.”

But, even with limiting, some apps like streaming or A/V playback have more leeway. This multi-tasking tends to compound into excess heat.

The best way to fix excess background services running is to become a minimalist in the number of installed apps. I recommend scrolling through your apps list, asking the question:

Is it worth 5% of my battery power today?

I know this is very Marie Kondo-like. But if you don’t use an app on at least a weekly basis, you’ll gain

  • a fuller battery
  • useless of your data plan
  • have more free storage space
  • most importantly, not heat up your phone

Remember that you can always reinstall apps if you need them later.

Outdated, Poorly-Written, Side-Loaded, Hacked Apps

Not all apps are created equally.

Some mobile apps are poorly written or can become out of date. This inefficient code or unnecessary processing drains your battery and can cause an overheated phone.

As mentioned in the last section, becoming a digital minimalist in app count can reduce the chances that rogue apps do not cause problems. For the remaining apps, be sure they’re kept up-to-date along with your mobile operating system, Android and iOS.

The apps you use frequently should only be installed from official and well-known app stores. Downloading apps from the Google Play Store and Apple App Store is always the safest route. For the tech-savvy and privacy-conscious, F-Droid and Aurora stores are well vetted.

For Goodness Sake:

Please do not get a premium or paid version of an app from shady download sites. These apps have a higher likelihood to have been hacked. Installing these dodgy versions on your smartphone, where you keep sensitive and private information, is a recipe for having your information stolen. On top of compromising your digital life, these hacked apps aren’t updated through an app store and can lead to making your phone hot.

A returning trend is to find ways to get a cryptojacker app installed on mobile devices, even from the official app stores. These apps are designed to mine cryptocurrency without the user’s knowledge.

Woman using smartphone in the dark in bed while her phone gets hot

Too Much Phone Use

Smartphones have become a revolutionary piece of tech expected to be used by 7.5 billion people worldwide by 2026. This indispensable device has downsides, though.

Many people use their electronic devices more than a “healthy amount.” While burning through your battery and heating your phone, you’re also negatively impacting sleep, attention, posture, and potentially a list of other yet-to-be-identified aspects of your health.

Some solutions to too much phone use can include simply:

  • Taking a break – Take a break from using a smartphone, and you may even consider doing a digital detox.
  • Live at the moment – It includes taking a quick walk, going outside to have some fresh air, or having a conversation with those around you.

Side Note: Unfortunately, kids get bored quickly unless they have access to devices like cell phones, tablets, or video games. My partner and I have begun detoxing our kids, teaching them to find new real-world skills, hobbies, and outlets for imagination.

Needs Servicing Or Replacement

While most mobile phone hardware has been designed for the rigors of daily use, an overheating cell phone might point to a need for servicing.

Many of the most common reasons leading to a hot phone include:

  • Dropping your phone on the ground or into the water
  • Malfunctions in older hardware components
  • Repeated exposure to heat, cold, or fluctuating extreme temperatures
  • Environmental debris infiltrating the device components (dirt in your phone 🙂

The best solution is to bring your phone to a repair shop to have an experienced professional inspect the device for internal physical damage. Let them know about any recent damage or exposure to heat sources.

Suppose the repair technician cannot find any hardware-related problems and the device still produces excessive heat. In that case, it might be time for an upgrade. As components age, they cannot keep up with today’s apps and user multi-tasking.

The average smartphone lasts only around three years. Look to replace your phone as soon as your budget allows.

Mike Chu

Mike is a web developer and content writer living as a digital nomad. With more than 20 years of devops experience, he brings his "programmer with people skills" approach to help explain technology to the average user. Check out his full author bio by clicking here.

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