Cool Prime Comparative Effectiveness Study for Mild HIE

To determine effectiveness of therapy to improve neurodevelopmental outcomes in infants with mild HIE. To determine the adverse effects of Therapeutic Hypothermia (TH) in mild HIE on the neonate and his/her family. Determine heterogeneity of the treatment effect across key subgroups obtained in the first 6 hours after birth prior to the decision to initiate therapy.

Inclusion Criteria: Infants must meet all 3 inclusion criteria 1. Neonates born at ≥ 36 0/7 weeks 2. Mild Encephalopathy on neonatal neurologic exam within 6 hours after birth: defined as presence of at least 2 signs of mild, moderate, or severe encephalopathy with no more than 2 signs in the moderate or severe category. 3. Perinatal Acidosis based on at least one of the following (A or B): 1. pH ≤ 7.00 in any cord or first infant gas (arterial, venous, or capillary) within ≤ 60 min OR base deficit ≥ 16 in any cord or first infant gas (arterial, venous or capillary) within ≤ 60 min 2. If pH is between 7.01 and 7.15, OR base deficit is between 10 and 15.9 mmol/liter, OR blood gas is not available, an acute perinatal event is an additional criteria required (see below definition) An acute perinatal event is defined by at least one of the following: 1. Apgar score at 10 min ≤ 5 2. Continued need for resuscitation at 10 min (chest compressions, bag mask ventilation, or positive pressure ventilation) 3. Uterine rupture, placental abruption, cord accident (prolapse, rupture, knot or tight nuchal cord) 4. maternal trauma, maternal hemorrhage, or cardiorespiratory arrest 5. fetal exsanguination from either vasa previa or feto-maternal hemorrhage, shoulder dystocia 6. Any evidence suggestive of acute perinatal event. Infants are still eligible for enrollment in the COOLPRIME study if the cord or infant's first blood gas (arterial, venous, or capillary) is obtained \>60 minutes of life. Exclusion Criteria: 1. Gestational age at birth \< 36 0/7 weeks 2. Birth weight \< 1800gm 3. Head circumference \