1. Charging under pillows
Placing your smartphone under a pillow while charging is a widespread habit, but it poses serious safety risks. When a phone charges, it generates heat as part of the normal electrical process. Under a pillow or any soft bedding, this heat cannot dissipate effectively because the materials block air circulation.
This trapped heat causes the phone’s internal temperature to rise, which can accelerate battery wear and damage internal components. More critically, overheating can lead to battery swelling or, in rare situations, ignite a fire. Firefighters frequently respond to home fires linked to electronic devices left charging in unsafe locations like under pillows.
2. Overheating risks
Overheating is the primary hazard when charging smartphones in enclosed or insulated environments. Modern phones include built-in safety mechanisms designed to regulate charging and prevent excessive heat. However, these systems are not foolproof, especially when the device is covered by blankets or surrounded by soft materials that trap heat.
Continuous heat buildup can cause the battery’s chemical components to degrade faster, reducing battery life and potentially causing malfunctions. If the phone remains overheated for hours, such as overnight charging under a pillow, the risk of thermal runaway—a condition where the battery generates more heat than it can dissipate—increases substantially. This scenario can lead to smoke, fire, or even explosions in extreme cases.
