Kevin I know for a fact I don' t have ciculation problems, that would be a quick and easy answer for my getting so cold. I am 28 years old, a nurse, and in perfect health unless I die in my sleep tonight. The Heater Body Suit isn' t operated by any batteries or anything. It is this big, bad, high dollar camo sleeping bag with legs. That pretty much sums it up. It has a " you won' t get cold or your money back gurantee" . Now in my short life I have learned that a) these people must have a pretty good product or b) they say that to get your money and then you are screwed. That is why I was trying to get some input on it before I pissed another $300 dollars in the wind on " WARM" hunting clothes. Check it out at heaterbodysuit.com and see it.