Pillows can trap charging heat, risking phone damage or fire

The main danger of charging a phone under a pillow is trapped heat, which can damage the device and, in rare cases, cause burns or fire. This risk matters more than fears that phone radiation will cause cancer: the article says current evidence does not indicate an increased risk of several brain and head tumours from mobile phone use.

Phones generate heat while charging, and pillows or blankets restrict airflow. Repeated overheating can shorten battery life, damage components or, in rare cases, contribute to thermal runaway, especially if the battery is damaged or the charger is uncertified. The article recommends charging on a hard, flat, well-ventilated surface.