Hydrogels are water-swollen polymer networks capable of absorbing large amounts of water or biological fluids. Their biocompatibility and ability to release encapsulated substances make them ideal for controlled drug delivery systems, ensuring a sustained release of medication. While they can have some cooling properties due to water evaporation, their primary use in air-conditioning is limited compared to dedicated cooling technologies. Their application in industrial lubricants is also less common compared to specialized lubrication materials.