When babies are hungry, bottle food should never be too hot or too cold. For this reason, mums and dads check the drinking temperature before every meal. Knowing exactly when the right temperature is reached can be a challenge. That's why NUK First Choice+ baby bottles with Temperature Control function were developed.This is a function that has not yet existed in this form before. To help from feeding the contents of the bottle too hot to your baby, NUK First Choice+ baby bottles now feature the new NUK Temperature Control Indicator. It looks like a thermometer, is located within the graduation marks and the temperature of the contents of the bottle makes it change colour. In the future, the function will help parents to achieve the optimum temperature when feeding their baby.If the food is too hot, the normally blue indicator will turn white. Ideally, the food for feeding should have body temperature (37°C) and corresponds to the mean blue tone on the display. The new Temperature Control function is integrated in NUK First Choice+ bottles made of polyamide and polypropylene.