Section 890.5720 - Water circulating hot or cold pack(a)Identification. A water circulating hot or cold pack is a device intended for medical purposes that operates by pumping heated or chilled water through a plastic bag and that provides hot or cold therapy for body surfaces.(b)Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 890.9 .48 FR 53047, Nov. 23, 1983, as amended at 63 FR 59231, Nov. 3, 1998