 Patients admitted into Vancouver Hospitals ICU are eligible for this study if they have a new fever and meet the inclusionexclusion criteria. Study participants will be randomly assigned into one of 2 study arms, the control group and the 650mg group. Study participants in the control group will receive 2 capsules of placebo and the 650mg group will receive 2 capsules of 325mg acetaminophen. Data continuous measures of temperature, heart rate and blood pressure will be collected from the time of the study drug administration until 6 hours post. All patients, health care workers, and researchers will be blinded to which arm the patient is enrolled in until the end of the study. The incidence of fluid bolus administration, increases in vasoactive drug use, will be recorded and compared. We will also compare blood pressure data, and fever burden between the 2 groups. 