NUK Extra Cool Teether: cools longer than conventional teethers., , Babies explore their surroundings extensively in the first few months. Toys, their mothers thumbs or their bottles are examined not only with their little hands, but also with their mouths. The first little teeth are quick to appear and this further intensifies the craving to chew and bite. , , The NUK Extra Cool Teether helps to distract your little treasure from the teething pains, so that your baby is quickly cheered up again. The teether is filled with sterilized water and can be cooled in the refrigerator. This cooling has a calming effect on your baby's irritated gums. Compared to conventional teethers, the NUK Extra Cool Teether cools longer. But take care: teethers do not go in the freezer compartment! If they are too cold, they can cause frostbite on the lips or inside the mouth.