I should add for someone who may be wanting to use this for a prolonged period, that one of the things Ive noticed this does is to increase circulation, that being a good thing, but in doing so in todays world, it can make a potentially toxic drug like tylenol, acetamenophen etc more effective even though it would not raise the blood level of the drug , and thus ome was already near a toxic level, this may potentially push the drug beyond the toxic point, although only while having one's hand in the fetal position, and the toxic effect stops within less than a minute once one puts his hand down.