Hydrogels are water-swollen polymer networks with high water content, making them biocompatible and capable of absorbing and releasing substances. This property is crucial for controlled drug delivery systems where the hydrogel matrix can encapsulate drugs and release them slowly over time, responding to physiological conditions. While some water-absorbing materials are used in cooling, hydrogels are not a primary component in typical mobile air-conditioning systems. Their primary application in lubrication is limited compared to their widespread use in biomedical fields.