I've had many colonic therapists over the yrs who have recommended to me castor oil packs & I use them. I do fall asleep with it on sometimes. I have a heating pad now that is like really strong but you have to push the button every so often so this is not so much of an issue now. I've always hated that dumb button but now I think I like it, lol.
You kinda have to hold it for awhile is the annoying part.
Okay well they have always told me to use #1 a low setting (but I don't have that option on mine)
and #2 no more than for an hour.
Just my two cents. i wear it longer almost every time, due to poor planning, putting it on late at night etc.