Hypothermia is a common symptom, generally we talk about hypothermia refers to the body temperature is more than normal, but below 38 ℃, caused by many causes of hypothermia, such as infection bacteria or viruses, teething, blood system diseases, drug fever are common in infants and young children. 1, infectious hypothermia: bacterial and viral infections, check the blood routine to clarify the diagnosis, give the appropriate anti-inflammatory and anti-viral drugs to deal with, with reasonable drugs, about three days should be able to relieve. 2, the child during teething: accompanied by obvious irritability, like to bite things, gums red and swollen, some babies may be accompanied by low fever, give the baby a light diet, you can try a little cooler food to relieve the discomfort of the gums, generally soon the temperature will drop to normal. 3, the child for a long time with drugs: will be the accumulation of drugs lead to drug fever, the results of various auxiliary tests are normal, there is a certain history of long-term intake of drugs can be diagnosed. About 1 to 2 weeks after discontinuing the drug, it should be able to return to normal. 4, blood system diseases: children with long-term low-grade fever, blood routine with obvious abnormalities, antibiotic treatment is ineffective, should be pediatric hematology professional consultation, according to the need to choose the appropriate examination, indeed for the blood system diseases, give the corresponding radiotherapy or chemotherapy treatment. Low fever generally does not require antipyretic drugs, but only physical cooling for the child with the use of warm towels to wipe the armpits, forehead, groin.