It sounds like you’re referring to a warning about placing a charger incorrectly. A common safety warning is:
Never put a charger under a pillow, blanket, mattress, or other covered surface while it is plugged in.
The charger can trap heat, overheat, and potentially damage the charger, device, or surrounding materials.
Other charger safety tips:
- Do not use a charger with frayed wires or a cracked adapter.
- Keep it on a hard, open surface where air can circulate.
- Avoid charging near water.
- Unplug it when not in use if it becomes unusually hot.
- Use chargers from reliable, compatible sources.
If you mean a specific position shown in a picture or video, send the image and I can explain what the warning is about.