The cold temperature of the cap constricts the blood vessels beneath the skin of the scalp, preventing the chemotherapy medicine from reaching the hair follicles, therefore allowing the patient to preserve their hair. This process is referred to as vasoconstriction. The cold also slows down the hair follicle metabolism, making the hair cells dormant or less active, further preventing the absorption of chemotherapeutic drugs
***From Our Experience, ONLY purchase the new as the refurbished can be quite worn and may not make it through the entire course of chemo***