Within 6 hours of birth, infants will be randomized to either a non-cooled control group with rectal temperature kept at 37+/-0.5 degC or to head cooling with mild systemic hypothermia as follows. A cooling device capable of circulating cool water in a temperature-regulated manner through a cap fitted around the infant's scalp will cool the head. The core rectal temperature of the infant will be maintained at 34.5+/-0.5 degC by adjusting the cap water temperature. The infant's rectal, nasopharyngeal, scalp (fontanel), and skin (abdominal) temperatures will be continuously monitored. Also, metabolic, cardiovascular, pulmonary and coagulation laboratory measurements will be assessed at predefined time points. Cooling will be maintained for 72 hours, followed by four hours of rewarming, with the goal of raising the rectal temperature to normal body temperature by 0.5 degC per hour. The outcome measure of severe neurodevelopmental disability and survival rates at 18 months of age will be assessed by blinded, independent observers.