U.S. patent application 20180103714 (applicant Under Armour, Baltimore, Md.):
"The present invention is directed toward an article of footwear effective to regulate the temperature of the feet of a wearer. In an embodiment, the article of footwear includes an upper and an insole with a thermal effect membrane. The thermal effect membrane contains a plurality of system-reactive components selectively engaged heat and/or moisture. In an embodiment, the printed coating includes a cooling agent, a phase change material, and a heat dissipation material. The bottom of the sole structure of the article of footwear further includes a multiple openings in the forefoot, midfoot, and hindfoot regions. The multiple openings promote airflow into the interior of the upper. In operation, the article of footwear is effective to delay/diminish the rise in skin temperature (compared to footwear lacking the membrane and/or openings), increasing wearer comfort."