Do not use when driving, operating machinery, or similar actions needing muscular control. Do not use to mask or relieve undiagnosed pain. This may delay diagnosis of a progressive condition. Do not use if you have, in the area being treated: active or suspected cancer or undiagnosed pain with a history of cancer. Stimulation directly through a confirmed or suspected malignancy should be avoided as it may stimulate growth and promote spread of cancer cells. Do not use simultaneously with high frequency hospital diagnostic/ therapeutic equipment. Doing so may result in burns at the site of the electrodes and possible damage to device. Do not use electrodes on the front of the neck. Do not use electrodes across the chest. Very strong stimulation across the chest may cause an extra heartbeat and/or rhythm disturbances to your heart, which could be lethal. Do not apply near the thorax Stimulation should not be applied across or through the head, directly on the eyes, covering the mouth, on the front of the neck