In a 3-month period (January to March, 1992), patients with rectal temperature below 35 degrees C detected by an electrical rectal thermometer (Diatek, Inc, San Diego, CA) were enrolled. In addition to treatment of the underlying diseases, the patients were rewarmed with either a heating lamp (core temperature > 32 degrees C) or warm fluid intravenous infusion and/or gastric lavage (core temperature < 32 degrees C). Patients' vital signs, serum potassium, pH, initial temperature, mean weather temperature, underlying disease and outcome were recorded and compared between survivors and non-survivors. We collected 23 cases with mean age of 71.6 years and mean core temperature, 33.32 degrees C (29.4-34.9 degrees C). The diagnosis included hypoglycemia in 7 cases, sepsis in 3 cases, active TB in 2 cases, HHNK in 1 case, DKA in 1 case, UGI bleeding in 1 case, parkinsonism in 1 case, intracerebral hemorrhage in 1 case, urinary tract infection in 1 case, brain tumor post operation in 1 case, arrhythmia in 1 case, senile dementia in 1 case, COPD in 1 case and lung CA in 1 case. 12 (52%) cases died during admission. No significant difference in clinical parameters was noted between survivors and non-survivors. In conclusion, although in subtropic area, the hypothermic patients in our country cannot be overlooked. As patients are usually elder and have other diseases, the prognosis is correlated with the severity of the underlying disease. Alert, intensive care, prevention and treatment of the complications that arouse, and careful rewarming are necessary for management of such patients.