Inclusion

Coma after OHCA
> 18 years old
Cool to <34°C within 4h of 911 call
Definitive temperature device initiated (arctic sun or alsius catheter
Enroll within 6h of start of cooling
Informed consent from LAR

Exclusion

Known pre-existing neurological disability
Known pre-existing terminal illness
Planned early withdrawal of life support
Presumed sepsis
Prisoner
Hemodynamic Instability