 Continuous pulse oximetry monitoring is the standard of care in critically ill patients in emergency departments, operating rooms and intensive care units. In patients with poor peripheral perfusion low blood flow due to peripheral vascular disease, low body temperature, or shock and the use of medications to raise the blood pressure, clinicians have difficulty obtaining an accurate measurement. This study compares the accuracy of forehead oximetry sensors to nasal alar sensors to lab oximetry measures and on the rate of device related pressure ulcers with both. 