['To measure the effect of ice slurry topical cooling on brain surface temperature during deep hypothermic circulatory arrest.', 'This was a prospective, controlled experiment.', 'Animal laboratory at a university hospital.', 'Five control lambs, five treatment (ice slurry) lambs.', 'Animals were studied in two groups: the study group had topical cooling of the head with ice slurry started immediately before circulatory arrest and continued throughout the period of circulatory arrest; control group lambs received no supplemental topical cooling.', 'Brain surface temperature, scalp, nasopharyngeal, and rectal temperatures were measured at 5-minute intervals during 45 minutes of circulatory arrest. Lambs receiving topical cooling of the head with ice slurry had a statistically significant decrease in brain surface temperature of 2.2 +/- 1.2 degrees C during circulatory arrest, whereas brain surface temperature increased 1.2 +/- 0.3 degrees C, in control lambs. Equilibration of temperature between the scalp and brain in control lambs produced rewarming of the brain surface.'] Does topical ice slurry prevent brain rewarming during deep hypothermic circulatory arrest in newborn sheep?