Therapeutic hypothermia is currently recommended neuroprotective therapeutic measure for comatose patients after cardiac arrest. Hypothermia has been proven not only to affect the neurological outcomes but also the survival of patients after cardiac arrest. This communication summarizes the issue of early infectious complications in patients after cardiac arrest undergoing therapeutic hypothermia. Diagnosis of infectious events is complicated in patients after cardiac arrest not only by the physiological effects of therapeutic hypothermia but also by the consequences of reperfusion injury and development of postresuscitation disease associated with systemic inflammatory response syndrome. Furthermore, there are discussed limited diagnostic options of infectious complications. The significance of the usual symptoms of infections is reduced, as well as the value of laboratory markers such as procalcitonin and C-reactive protein. Finally, the possibility of antibiotic treatment and eventual antibiotic prophylaxis during therapeutic hypothermia in patients after cardiac arrest outside hospitals is mentioned.