Hydrogel cold compresses belong to the sterile medical device?

Depends on the intended use, class I, II and III are possible.

For example:

Fever-reducing patches : textile cloth, menthol, parabens, water, polymer substances (including glycerin). Intended use of the product : With the help of water, ethanol evaporation and heat dissipation, so that patients with fever can be physically cooled down. This belongs to a category.

Disposable medical hydrogel eye patch: composed of medical polyvinyl alcohol. Used to apply general anesthesia surgery patients or deep coma patient's eyes outside, to provide patients with a relatively closed moist environment, to prevent exposure keratitis. This belongs to the second category.

Isotonic saline gel: mass ratio of 0.9% sodium chloride colloidal solution. The components are water, sodium chloride, and Xanthomonas gel. Intended use of the product: to keep the wound moist and thus produce autolytic debridement of the wound. This one belongs to category III.