Why Is My Phone Overheating?

All phones generate heat — that’s normal. The processor is doing real work, and that work produces warmth. But there’s a difference between a phone that’s warm during a long video call and one that’s uncomfortably hot while sitting idle on a table. The first is fine. The second is worth looking into.

1. What Causes Normal Warmth

These situations will make your phone warm, and none of them are a problem:

• Charging: Especially fast charging. The phone converts electricity to stored energy, and that process generates heat. Perfectly normal.
• Demanding apps: Games, video editing, sat nav running in the background, or streaming video at high quality all push the processor hard. Warmth is expected.
• Hot environments: Direct sunlight on a phone in a car, or a pocket on a warm day, will heat the device even if it’s doing nothing intensive.

2. Background Apps and Software

The most common cause of unexplained overheating is an app that’s stuck running in the background — something you’ve closed on screen but which is still consuming processor or data resources. Social media apps, navigation, and anything that syncs in real time are common culprits.

A full restart clears these. If the phone runs cooler after a restart, that confirms a software process was the issue. If the problem keeps coming back, check which apps are using the most battery in settings — an app using an unexpectedly high percentage when you’re not actively using it is a red flag.

Software updates can also cause temporary overheating in the hours after installation as the phone reindexes and completes background processes. This usually settles within a day.

3. Charging While Using the Phone

Using your phone heavily while it’s charging compounds the heat from both activities at once. The phone is generating heat from the charging process and from whatever you’re doing. If you need to charge quickly, putting the phone down and letting it charge idle will be faster and cooler.

4. The Battery Is the Real Warning Sign

This is the scenario that matters most. As lithium batteries age, they become less efficient at managing charge cycles. An aging or degraded battery generates more heat during charging and discharge than a healthy one, and it can also cause the phone to work harder to compensate for reduced power delivery.

Warning signs that the battery is the issue:

• Phone gets hot while charging, even if you’re not using it
• Phone gets hot quickly on light tasks that never used to cause warmth
• Battery percentage drops fast and erratically
• Phone shuts off before the battery reaches 0%
• The back of the phone feels swollen or slightly raised (this is a swollen battery and needs immediate attention — stop using the phone and bring it in)

A swollen battery in particular is not something to ignore. It’s a sign the battery is failing and can in rare cases be a fire risk. If the back of the phone feels raised or the screen appears to be lifting from the frame, bring it in straight away.

5. The Case Can Make It Worse

Thick rubber or leather cases insulate heat instead of letting it dissipate. If your phone is running hot, removing the case often helps significantly. Some people notice their phone runs warm not because of any fault, but simply because the case traps heat during charging. Switching to a slimmer case or going caseless while charging can make a noticeable difference.