Recurrent low-grade fever for 2 days during breastfeeding can be continued if it is a cold or mastitis, but if it is an infectious disease of unknown origin it is recommended to be evaluated by a doctor before deciding whether or not to continue breastfeeding. Fever is a symptom of illness, and fever itself does not affect the composition of breast milk. Colds are caused by respiratory viruses, which can be transmitted by droplets, and are not passed on to the baby through breast milk, and breast milk allows the baby to produce antibodies that help the baby fight the virus. Mothers need to do a good job of hand hygiene, wear a good mask when contacting the baby to prevent the spread of droplets, and then breastfeeding. If the fever is caused by mastitis, it is more important to breastfeed. It is necessary for the baby to suck out the milk frequently and effectively in order to relieve the milk stagnation more quickly, which will help to unclog the milk ducts and relieve the mastitis fundamentally. If the cause of the fever is unknown, you can’t rule out the possibility of other pathogens, so you need a doctor to make a clear diagnosis before deciding whether or not to continue breastfeeding. In addition, many medications may be secreted through breast milk, and breastfeeding mothers need to consult a doctor of the relevant specialty or department on the use of medications.