The invention is directed to a mouth piece for cooling of oral tissue of a patient during chemotherapy treatment. The mouth piece includes a cooling medium contained within the top element and the bottom element and able to retain a cooling environment within the mouth sufficient to reduce capillary blood flow to the patient's mouth. In one embodiment, an external chamber extends from the front of the mouth piece to house a cooling medium. A bladder is positioned inside the external chamber for storing a solution having a freezing temperature above the freezing point temperature of the cooling medium to assist in cooling the cooling medium.
