Heat-venting insulating article

A heat-venting, insulating article including an intermediate heat-insulating layer provided with a plurality of through holes, and a heat-venting ring fitting in each of said through holes in said heat-insulating layer, each of said rings comprising an intermediate relatively small-sized portion between relatively large-sized end portions, said intermediate portion including a transverse separating layer comprising two semi-circular petals made of a soft flexible material and each including a diametrical edge, each of said petals being provided with a through pin hole in the diametrical edge thereof and said article further comprising a U-shaped metal pin having first and second legs inserted into respective through pin holes of said petals, each said metal pin being capable of expansion or contraction in response to a rise or fall in temperature, each said metal pin expanding to bend and push the two petals to both sides so as to form an opening between the two petals to let heat flow through when the metal pin is heated by body heat from a user of the article, and each said metal pin contracting to close the two petals when the metal pin cools off.