It heats fast, hard to find the right setting for you.
I have ran into several red light devices that say not to use if you have in this case Thyroid or heart problems.  I have thyroid problems, I never noticed the warning in the descriptions.  So if you have either do not buy this device. Others have said Glaucoma.<br />My husband did use it and could not get comfortable.  He said it was very hot on his neck.  As you can see we used all three levels.  It got to the point of too hot.<br />It does lay right on your skin in back.  It even looked hot, seeing him wear it.<br />I cannot say this would be a good item to recommend.<br />I hope this review helped you.
Rating: 2 stars