It "works" on the same principle of dipping your fingertip in a bottle of rubbing alcohol -- the cooling sensation your fingertip experiences is caused by the removal of heat energy from evaporation.
Since alcohol would obviously evaporate too quickly and would probably set off some alarm bells, water is used in the FRIO. Thus, water doesn't cool as quickly as FRIO, but it works, mostly in dry climates. If you're going to be in a humid environment, like a rain forest or for long periods in a steamy sauna or shower, then it's no good. (That was a bit of a joke).
You can make these for a lot less, if you have some sewing skills. I'm surprised they got a patent for the pouch, because I've seen what they do in sweatbands (not ones they sell) and yet they still received a patent. It's simply a material pouch that has sewn in to it water-absorbing (hydroscopic) beads which you can buy large quantities of for small amounts of money in a lawn and garden store (it's the gel material some people mix with their soil to keep it moist longer).
The fabric they use is actually resistant to mold -- so the typical fabric that you would find in a sewing shop would probably not be ideal. I can't recall the name of the fabric they use in the product, but several years ago, I did find a website that sold it (and also provided samples).
I imagine that a person could relatively easily challenge their patent and sell their own FRIO-type cooling wallets by showing prior art and the simple fact that I don't think you should be able to patent a rule of physics, as well as the hydroscopic plant gel beads that they use, as well as the fabric that they buy from a major fabric supply manufacturer. Although, I guess a company can put a trademark on something like a dress, but that shouldn't stop some other company from coming out with a dress that is slightly different, right?
I think it's funny that they claim to have received "FDA approval" -- I could never locate any sort of FDA approval documents on the FDA's website.
Like most diabetes inventions, the person who develops it also decides they must get rich while the item is popular. We can only thank Banting and Best for not having the same mindset when discovering insulin.
How did I get off on this rant? lol
