Background: the mechanisms responsible for shivering in patients undergoing surgery are intra-operative temperature loss increased sympathetic tone, pain, and systemic release of pyrogens, and the direct effect of local anesthetic temperature on temperature-sensitive neurons in the spinal cord. 
Objective: to compare the effects of warm intrathecal bupivacaine versus cold intra-thecal bupivacaine on shivering and haemodynamic stability in parturient candidate for elective lower limb orthopedic surgery under spinal anesthesia.
Patients and Methods: the current study was carried out in in Alexandria Police hospital, on 80 parturient, aged 20-60 years old, ASA I-II, scheduled for elective lower limb orthopedic surgery under spinal anesthesia, after the approval from the Local Ethical Committee and informed written consents from all the patients of the study. Patients were randomly allocated into two equal groups (40 patients each); group R (Warm group), group C (Cold group).
Results: Comparison between the two studied groups showed no significant statistical differences at all the measured times.
Conclusion: Shivering continues to be a common problem after spinal anesthesia. The etiology of this symptom is unknown, and there is no definite treatment.