The purpose of this multination multicenter observational study is to determine the impact of fever and antipyretic on outcomes in critically ill patients.

Fever is common in critically ill patients.Antipyretic therapy for fever is routinely performed in intensive care.There are studies to assess the relationship between fever and mortality in non-neurological ICU. However, all of them did not have any information of antipyretic therapy. There are two small, single center RCT, which suggested a potential risk for antipyretic therapy. Thus, a large RCT might be ethically difficult.

It is unfortunate that there is not enough information on how the investigators should control body temperature in non-neurological critically ill patients, because fever is a very common physiological abnormality in this cohort. From the beginning, it would, therefore, be desirable to understand several aspects of fever and antipyretic therapy in ICU patients, as 1)How often fever occurs in our ICUs, 2)To what degree fever is independently associated with mortality?, 3)How often antipyretic therapy is prescribed?, 4)How effectively antipyretic can decrease temperature?, 5)How different is lowering temperature with medications compared with cooling?, 6)To what degree antipyretic is independently associated with mortality?

Thus, the investigators plan to address these questions by conducting a multi-national multi-center prospective observational trial, named "The Fever and Antipyretic in Critically illness evaluation study" (The FACE study)

Inclusion Criteria:

• Adult non-neurological critically ill patients (20 years old or older).
• ICU patients expected to require intensive care for more than 48 hour.

Exclusion Criteria:

• Patients with brain injury (suspected or proven)

Adult non-neurological critically ill patients required intensive care for more than 48 hour.