Figure 36-8 Temperature correction of blood PO₂ : percentage error of PO₂ measurement at various body temperatures with the blood gas electrode at 37°C. If the patient's temperature is 20°C, a PO₂ measurement performed at 37°C would overestimate the true value by more than 200%. The curves demonstrate that the percentage of error is greater for venous values (PO₂ < 100 mm Hg) than for arterial measurements (PO₂ > 300 mm Hg). (Adapted from Camporesi EM, Moon RE: Arterial blood gas values should be corrected for body temperature during hypothermia. In Fyman PN, Gotta AW [eds]: Controversies in Cardiovascular Anesthesia. Boston, Kluwer Academic Publishers, 1988, p 35.)