Before you begin, make sure you have a plan in the event of a fire. If you have a swollen battery, take appropriate precautions.

Keep the hair dryer switched off and unplugged when not in use.

Avoid using extension cords to power your hair dryer. Since hair dryers require a high current draw, cheaper or old extension cords pose a greater fire risk.

Never heat a battery directly. If you're heating adhesive near or underneath a battery, make sure you've completely discharged the battery before applying heat.