Intrathecal DEX With Bupivacaine Inpost-spinal Shivering After CS.

Inclusion Criteria: * Full-term pregnant women undergoing elective cesarean section under spinal anesthesia. * singleton pregnancy * Age: 20 \~ 40 years; * ASA physical status II \~ III; Exclusion Criteria: * parturient less than 20 years and more than 40 years. * History of uncontrolled comorbidities, cardiac (e.g., pre-eclampsia and hypertension), respiratory, renal or hepatic disease. * parturients who had allergy to any medication in the study. * parturients with contraindications to spinal anesthesia (coagulation disorder, infection at site of puncture, raised intracranial tension or any spine deformity) * parturient who has history of alcohol intake. * parturient received any medication likely to affect thermoregulation or Veno dilation. * Refusing to sign informed consent.