Back Cover: In article 2300261, Chuanzhuang Zhao, X. X. Zhu, and co-workers summarize the synergistic approaches in the design and applications of thermoresponsive polymers with upper critical solution temperature (UCST) in aqueous systems. Synergy of hydrogen bonding with other types of physical interactions not only enables precise control of the responsive behavior, but also leads to emergence of novel functions of UCST polymers.