Figure 40-25 Axillary and esophageal temperatures correlated well during acute malignant hyperthermia in swine, but forehead and neck skin temperatures did not. Rectal temperature also failed to promptly identify the onset of malignant hyperthermia. Elapsed time zero indicates an end-tidal PCO₂ of 70 mm Hg. These data indicate that forehead and neck skin surface temperatures will not adequately confirm other clinical signs of malignant hyperthermia. Valid core temperature monitoring sites include the distal part of the esophagus, pulmonary artery, nasopharynx, and tympanic membrane. Except during cardio-pulmonary bypass, body temperature can also be measured in the mouth, axilla, and bladder. Data are presented as means ± SD. (Redrawn with modification from laizzo PA, Zink RS, Kehler CH, et al: Skin and central temperature during malignant hyperthermia in swine [abstract]. Anesthesiology 77:A569, 1992.)