#patent
Early this summer, my daughter asked me to buy her a cooling ring to wear around her neck, and I purchased the product shown in the photo.
Inside the ring-shaped tube is a liquid that freezes (becomes solid) at temperature below 28 Celsius. When placed in the freezer, etc., it solidifies quickly and stays cold.
Since it is used around the neck, it cannot cool the whole body, but my daughter says that the part of the body that touches the ring feels cool and comfortable.
By the way, the enclosed instruction sheet mentioned the patent number (Japanese Patent No. 6895671).
If you are interested in the contents of the patent, please check it on J-Plat Pat. (Hiro)
JP,6895671,B : The neck cooling device