Summary and ConclusionThis study was carried out in Zagazig university hospital; we deal with 40 neonates complaining from hypothermia, and we investigated and managed them until discharge.The cases were classified into 3 levels according to the temperature measurment; mild (34 toThe main cause of neonatal hypothermia was spesis (52.5%).The risk of neonatal hypothermia was associated with prematurity as (57.5%) of hypothermic cases were premature, also the risk of hypothermia increased with decreased the weight, (55%) had birth weight (<2500gm).The hypothermic infants manifested mainly by lethargy (85%) refusal of feeding (75%), cyanosis (60%) and apnea (52.5 %).There were significant difference between hypothermic and control groups as regard sepsis screen (C.RP, TLC and blood culture) p<0.05.The hypothermic infants were significantly more likely to be acidemic (p=0.0001) hypoxic (p=0.003) and hypoglycemic (p=0.03) than normothermic infants. Moreover there were significant difference in serum potassium (p=0.042) and serum sodium (p=0.011) between hypothermic and control group.The complications associated with hypothermia were included thrombocytopenia (45%), respiratory failure (35%), oliguria (25%), convulsion (22.5%) and (NEC) (15%).The most cause of death in hypothermia was respiratory failure (35%) then pulmonary hemorrhage (30%).The mortality rate of hypothermia was (50%), on other hand the mortality affected by multiple factors (e.g) level of hypothermia; in severe hypothermia mortality was (83.3%), cause of hypothermia; in hypothermia with sepsis mortality was (71.7%) and gestation age; mortality of premature (We noted from the previous studies results that the neonatal hypothermia are still a serious problem which associated with high risk of morbidity and mortality.The outcome of hypothermia depending on multiple factors (risk factors, underlying causes, severeity of hypothermia, and the response for rapid and proper management of the patient).The hypothermic neonate need to rapid rewarming and immediately treatment of severe cases, rapid investigations for detection of the pathological causes of hypothermia with starting to treat the cause immediately to avoid prolongation of hypothermia and metabolic changes.