Comparison of Forced Air and Conductive Patient Heating Systems During Ambulatory Surgeries

Patients will be randomized into either the Forced Air group (FA) or Conductive Heat group (CH). Randomization will be based on computer-generated codes that will be maintained in sequentially numbered opaque envelopes. Fifty patients will be recruited with 25 patients being randomized into each group. In patients assigned to the FA group, a Bair Hugger (Arizant Medical, Inc., Eden Prairie, Minnesota) forced-air cover will be positioned over the upper body (if lower extremity surgery) or lower body (if upper extremity surgery). The forced-air blower will be set and activated per standard practice usually after prepping and draping. In patients assigned to the CH group, a VitaHeat (VitaHeat, Inc, Aurora, IL) conductive heating device will be placed under the torso of the patient. The device will be set and activated per standard practice usually just after positioning of the patient on the operating table. Patients in both groups will be otherwise draped per surgical routine. Ambient temperature will be maintained near 20°C. Temperatures will be recorded using a temporal artery thermometer.

Inclusion Criteria: patients undergoing orthopaedic outpatient surgeries over 18 years old Exclusion Criteria: allergic to material of bair hugger