Keep it dry. Use the device only if is not damaged.
Don't use the device when you're about to sleep or laying in bed. Also don't use it shortly before sleeping, it has a stimulating effect.
Do not use it when operating a machine or a car.
Make sure it is not squished or pierced/cut by anything.
Don't cover it when it's turned on, don't use it below pillows or blankets.
Don't leave it unattended if it's plugged in.
The max operating time is 15mins. Let it cool down after.
Use or store it never next to a heatsource.