Intravenous Tramadol and Magnesium Sulphate for Prevention of Shivering

Inclusion Criteria: \- American Society of Anesthesiologists (ASA) I and II physical status undergoing an elective surgery under spinal anesthesia. Exclusion Criteria: * history of uncontrolled comorbidities, cardiac, respiratory, renal or hepatic disease, patients who had allergy to any medication in the study, contraindications to spinal anesthesia (coagulation disorder, infection at site of puncture, raised intracranial tension or any spine deformity), fever \>38 Celsius or less than 36 Celsius, body mass index more than 35 and who has history of alcohol intake