Inclusion Criteria:  ASA 1-2-3 Scheduled for direct anterior-approached total hip replacement surgery under general anesthesia  Exclusion Criteria:  pregnant women  patients with:  peripheral neuropathy or other severe neurological pathology immunosuppression chronic renal insufficiency or severe hepatic insufficiency major congenital or acquired hemostasis disorders craniofacial dysmorphism or anatomical alterations of the upper airways known thermoregulatory disorders patients with a preoperative body temperature > 37.5°C.