Time to Target Temperature (T2TT) correlated to the best cerebral perforemance catergory (CPC). Temperature data between April 1995 and June 2008 were collected from 588 patients. The best cerebral performance category achieved within 6 months after cardiac arrest was used. A CPC of 1 indicates good cerebral performance (the patient is alert and has normal cerebral function). A CPC of 2 indicates moderate disability (the patient is alert and has sufficient cerebral function to live independently and work part-time). Such patients might have hemiplegia, seizures, ataxia, dysarthria, dysphasia or permanent memory loss, or other mental changes. A CPC of 3 indicates severe cerebral disability (the patient is conscious but dependent on others for daily support because of impaired brain function). A CPC of 4 indicates a vegetative state. Time is expressed in minutes from restoration of spontaneous circulation (ROSC) to hospital admission (admission), to first monitored esophageal temperature (Tes 1st), to start of cooling (Cool Start), and to esophageal temperature (Tes) of less than 34°C, 33.5°C, and 33°C. Data are presented as median and interquaritle range from the 25th to the 75th percentile.