Important Safety Instructions Not for Sleeping: To prevent burns, do not use while sleeping or if you are unable to feel temperature differences due to medication or medical conditions. Time Limit: For optimal safety, limit each session to 30 minutes or less. Charging Safety: Do not use the device while charging. Always disconnect the USB cable before putting it on your wrist. Consult a Doctor: If you have diabetes, poor circulation, or are pregnant, please consult a healthcare professional before use.