Many parents have encountered a baby with a low fever in the middle of the night, but the mental state during the day is quite good, and sometimes last for several days are this way, this time parents must pay attention to the following reasons for this situation: First, because the baby’s body functions are better during the day, so will not have a fever or low fever, to the night baby sleep, the brain is in a resting state, so can not inhibit uncomfortable situation in the body, so at night will be low-grade fever; second, because the baby is dehydrated will lead to such a situation, because the baby drink more water during the day, once the night after going to bed, no longer drink water, and before going to bed many parents will let the child eat high calorie, high nutrition things, thus generating a lot of heat, resulting in the baby is dehydrated, dehydration will cause low-grade fever; third, is the baby body There is inflammation, or upper respiratory tract infection, pneumonia, will cause the baby low fever situation. So it is recommended to take the child to the hospital for a routine checkup, and according to the results to prescribe the right medicine, let the baby drink more water and do not eat greasy food.