Hydrating Sleep Mask PLUMPS, REPLENISHES, REHYDRATES A clinically proven* hydration mask that locks in moisture overnight, for a radiant, younger-looking complexion upon waking. At night, your body temperature tends to rise as it goes into repair and recovery mode. As a result, your skin loses hydration whilst you sleep. This super-cooling gel mask fights the visible signs of tired, dull skin by helping to seal in hydrating actives throughout the night, leaving your complexion looking radiant.