Purpose: Postanaesthetic shivering occurs in 5-65% of patients. In addition to causing discomfort, it is associated with deleterious consequences. Our objective was to investigate the effect of 150/ag clonidine, at induction of anaesthesia, on perioperative core and peripheral temperature, incidence of postanaesthetic shivering and patients' perception of cold. Methods: Sixty ASA I or 2 patients scheduled for elective orthopaedic limb surgery were randomly allocated to group I, who received 150/Jg clonidine iv, or group 2, who received a saline bolus iv, before induction. In alI patients, anaesthesia was induced with fentanyl and propofol and maintained by spontaneous respiration (via a laryngeal mask airway) of oxygen, nitrous oxide and enflurane. Core (nasopharyngeal) and peripheral (dorsal hand) temperatures were recorded at induction and 15-rain intervals. Nurses, unaware of the treatment groups, recorded visible shivering in the recovery room, When cognitive function returned, patients were asked to grade their perception of cold on a I 0 cm linear analogue scale, higher scores indicating heat discomfort.Results: While core temperature decreased and peripheral temperature increased in both groups, there was no difference between the groups at any time. However, there was a lower incidence of shivering in the clonidine group (20% vs 66.7% P <0.00l ). Patients receiving clonidine felt warmer; thermal comfort score (median interquartile range) 5.9 (5.0-7.2) vs 5.0 (4.5-6.0), P <0.05).Conclusion: Clonidine 150 g iv at induction of anaesthesia reduces the incidence of shivering and patients' subjective perception of cold on emergence from general anaesthesia. R~sultats : Alors que la temp&ature centrale diminuait et la temp&ature pEriphErique augmentait dans les deux groupes, aucune difference if&at notEe entre les groupes. Cependant, I'incidence du flisson Etalt plus basse dans le groupe clonidine (20% vs 66,7%, P <0,00 I). La perception de chaleur Etait plus ElevEe chez les patients sous clonidine avec un score de comfort (mEdiane &art interquartile de) 5,9 (5,0-7,2) vs 5,0 (4,5-6,0), P <0,05). Conclusion : AdministrEe ~. (induction, la donidine iv r~duit rincidence du fdsson et [a sensation subjective de froid per~ue au r~veil apr~s une anesth&ie gEn&ale.