This study was registered to Australian New Zealand Clinical Trial Registry with serial number ACTRN12614000286640. After institutional review, board approval and informed consent 50 female patients; ASA (American Society of Anesthesiologists) class 1, ages between 18-45 years old were enrolled in this study. The surgeries performed were septorhinoplasty and tympanoplasty. 25 patients with menstrual cycle days from 1 to 10 (follicular group), 25 patients with menstrual cycle days from 18 to 24 (luteal group) were included in the study. Exclusion criteria were diabetes, thyroid disorders, obesity, irregular menstrual cycle and oral contraceptive usage. None of the patients was premedicated. All of the patients were monitored "Dräger infinity delta XL" to measure continuous noninvasive blood pressure, electrocardiograms, capnograms, core temperature and skin temperature. The skin temperature probe was installed in the middle of the forearm where the non-invasive blood pressure cuff was not bound. The intravenous fluid was used at the room temperature intraoperatively and fluid administration was given from the arm that skin temperature probe was not installed. The core temperature was measured with esophageal probe immediately after the intubation. The operating room temperature was maintained between 21-22 °C. Anesthesia was standardized in all patients and induced with propofol 2 mg/kg IV and rocuronium 0.5 mg/kg IV. Anesthesia was maintained with remifentanil infusion and sevoflurane in a mixture of nitrous oxide 1 L/min