Babies with low-grade fever that does not go away for a day and a night should be observed for changes in temperature as well as spirit, and physical cooling should be carried out in a timely manner, and if the symptoms worsen, medical attention should be sought promptly. Low fever, in terms of axillary body temperature, generally refers to a body temperature of 37.3 ℃ ~ 38 ℃. Babies with low fever for a day and a night, commonly caused by upper respiratory tract infections and other factors, can be temporarily without drugs to reduce fever. Should regularly measure the baby’s temperature, drink more warm water, warm water towel wipe and other ways to lower the temperature. Need to pay attention to observe the baby’s mental changes, if the spirit is good, can be temporarily observed. If the baby’s spirit deteriorates, the temperature rises, lack of appetite and other manifestations, or the low fever still persists, it is possible that the symptoms are aggravated, you should go to the hospital in a timely manner, to clarify the cause of the low fever, and then targeted treatment.