Its larger, brighter design makes it even easier than before to check your little one is resting at the correct temperature. A yellow glow suggests a comfortable temperature for children to sleep in, whilst a blue glow suggests it's too cold and a red glow suggests it's too high. The colours act as a handy tool so you know whether to cool or heat the room, to modify baby's clothing, to use a different tog Grobag Baby Sleep Bag or for non-sleep bag users to alter the level of bedding.