“…The problems associated with low T core were recognized later when thermometers could record lower temperatures (to 24°C) (Wunderlich and Seguin, 1871;Guly, 2011). Since 1967, when cardiopulmonary bypass revolutionized the treatment of hypothermic arrested victims (Davies et al, 1967;Kugelberg et al, 1967), pulmonary artery temperature became the gold standard for T core measurement in patients with severe accidental hypothermia . Concurrently, interest in alternative, less invasive sites for temperature measurement led to the auditory canal and tympanic temperature (Benzinger, 1959;Brinnel and Cabanac, 1989), and others investigated the effect of environmental factors (i.e., cold) on tympanic, esophageal, and rectal measurement (Marcus, 1973;Keatinge and Sloan, 1975).…”