After dividing the patients into two groups, sedation is performed with propofol and remimazolam, respectively, after spinal anesthesia. Compare the patient's body temperature change after surgery.

Patients in the study were randomly assigned to the propofol group (Group P) and the remimazolam group (Group R) in a 1:1 ratio. Study drugs are prepared in the same 50 ml syringe, double-blind to group assignment. All patients are not given pre-anesthetic medication, and body temperature, blood pressure, and heart rate are measured in the recovery room after surgery at 10-minute intervals from just before anesthesia induction to surgery. If hypotension or bradycardia occurs during surgery and is not corrected even after rapid fluid infusion, ephedrine is increased by 10 mg or glycopyrrolate 0.2 mg or atropine 0.5 mg is administered.

If spinal anesthesia is successfully performed, check the patient's anesthesia height. When the appropriate level of anesthesia is confirmed, Group P receives propofol at 25-100ug/kg/min and maintains the BIS at 70-80. Group R receives remimazolam at 1-20ug/kg/min and maintains BIS between 70-80. Both groups apply a conventionally used air heating device, and the operating room temperature is kept at 20 °C. If shivering occurs during surgery, the elapsed time from induction and the shivering grades are recorded.

At the end of the surgery, record total anesthesia time and surgery time, fluid dose, and drug use. After moving to the recovery room, the patient's body temperature, systolic blood pressure, diastolic pressure, heart rate, the incidence of shivering, and the grade of shivering are checked. When shivering occurs, a forced air-warming device is applied first, and if shivering continues, administer meperidine in 5mg increments until the patient is comfortable and record the total dose.

Inclusion Criteria:

• Those aged between 19 and under 65 who are undergoing surgery under spinal anesthesia at Wonkwang University Hospital.
• American Society of Anesthesiologists' physical status class (ASA) award class I-III.

Exclusion Criteria:

• Patients with fever before surgery
• Patients taking antipyretics before surgery
• Patients who are chronically using anti-inflammatory drugs
• High-risk patients with ASA class IV or higher
• Patient who refused sedation
• Patients with thyroid dysfunction.