Why does my phone get so hot?

Phones have no fans, so heat leaves through the case. Anything that raises the workload or blocks that path raises the temperature, and sustained heat is the main thing that permanently degrades a lithium battery.

What you'll need

• Your phone

Step by step

1. Work out whether it is hot during use or while idle.Hot while gaming or navigating is normal. Hot sitting on a desk doing nothing is not, and means something is running.
2. Check which app is using the battery.Settings, Battery. An app high in the list that you barely use is running in the background and is very likely the cause.
3. Take the case off, particularly while charging.Thick or insulating cases trap heat exactly where the phone needs to shed it. This is a common and easily fixed cause.
4. Keep it out of direct sunlight and hot cars.A phone on a car dashboard in sun reaches temperatures that cause permanent battery damage within minutes.
5. Stop fast charging overnight if it runs hot.Slow charging generates far less heat. Overnight there is no benefit to charging quickly.
6. Update the operating system and apps.Runaway background processes after an update are common, and are usually fixed in the following release.
7. Restart the phone.It clears stuck processes. If the heat returns immediately afterwards, an app is the cause rather than a transient state.
8. Consider battery age if it is persistent.Check the battery health figure. A degraded battery runs hotter and holds less charge, and replacement is much cheaper than a new phone.

Tips

• Heat is the main cause of permanent battery degradation. A phone kept cool keeps its capacity for years longer.
• Never cool a hot phone in a fridge or freezer. Condensation inside the case does far more damage than the heat did.
• Poor mobile signal makes a phone hot — it raises transmit power hunting for a tower. In a weak-signal area, wifi calling helps a lot.

Common mistakes

• Charging under a pillow or bedding — It traps heat and is a genuine fire risk as well as damaging the battery.
• Leaving a phone on a car dashboard — Direct sun through glass takes it well past its safe operating range and causes permanent capacity loss.
• Ignoring persistent heat — Sustained heat degrades the battery permanently and can indicate a fault worth checking while it is still under warranty.

Questions people ask