Using a multicentre adult patient database from Australia and New Zealand, we obtained the lowest and highest temperature in the first 24 h after admission to the intensive care unit after elective non-cardiac surgery. Hypothermia was defined as core temperature <36 ?C; transient hypothermia as a temperature <36 ?C that was corrected within 24 h, and persistent hypothermia as hypothermia not corrected within 24 h. We studied 50 689 patients. Hypothermia occurred in 23 165 (46 ) patients, was transient in 22 810 (45 ), and was persistent in 608 (1.2 ) patients. On multivariate analysis, neither transient (OR = 1.07, 95 CI 0.96-1.20) nor persistent (OR = 1.50. 95 CI 0.96-2.33) hypothermia was independently associated with increased hospital mortality.