The diagnosis of hypothermia is based on core temperature and may not be initially obvious, especially in cases where a history of prolonged environmental exposure is missing. Low reading thermometers are required to measure and monitor temperature. Laboratory investigation is directed at determining the underlying cause and complications and includes glucose, CBC, electrolytes, clotting profile, blood gas and EKG. Acid-base disorders are common, but do not follow a predictable pattern. Intravascular thrombosis, embolism, and DIC may occur. Electrocardiographic changes include PR, QRS, and QT prolongation, T-wave inversion, and a slow positive deflection at the end of the QRS (Osborn J wave). In addition to environmental exposure, causes of hypothermia include hypoglycemia, hypothyroidism, hypoadrenalism, hypopituitarism, CNS dysfunction, drug intoxication, sepsis, and dermal disease.