Inclusion Criteria1. Age 22 to 82 years old inclusive
2. Patient receiving IV rt-PA using standard guidelines (Appendix II) Page 23
3. NIHSS score ≥ 7 and ≤ 20 (right hemisphere) or ≥ 7 and ≤ 24 (left hemisphere) at the time of randomization
4. Pre-stroke mRS 0-1
5. Able to begin endovascular phase of hypothermia within 2 hours of tPA completion
6. Written Informed Consent, signed and dated by the patient (or patient's authorized representative)
Exclusion Criteria1. Etiology other than ischemic stroke
2. Item 1a on NIHSS > 1 at the time of randomization
3. Clinical symptoms consistent with brainstem or cerebellar stroke
4. Classic lacunar syndrome with imaging confirmation of small deep ischemia, but randomization will not be delayed for neuroimaging other than initial scan to exclude hemorrhage
5. Known contraindications to hypothermia, such as known hematologic dyscrasias that affect thrombosis (cryoglobulinemia, Sickle cell disease, serum cold agglutinins), or vasospastic disorders such as Raynaud's or thromboangiitis obliterans
6. Known co-morbid conditions that are likely to complicate therapy in the opinion of the investigator, e.g., i. Heart failure (NYHA class III and IV)* ii. Uncompensated arrhythmia iii. Severe Liver disease iv. History of pelvic or abdominal mass likely to compress inferior vena cava v. IVC filters vi. HIV positive vii. Clinically active hypo or hyperthyroidism viii. Renal insufficiency likely to impair meperidine clearance ix. Chronic ethanol abuse
7. Pregnancy (All women of child-bearing potential must have a negative pregnancy test, urine or blood, prior to therapy.)
8. Medical conditions likely to interfere with patient assessment.
9. Known allergy to meperidine or buspirone
10. Currently taking or used within previous 14 days MAO-I class of medication.
11. Life expectancy < 6 months
12. Not likely to be available for long-term follow-up
13. Use, or planned use, of intra-arterial thrombolysis, mechanical clot removal, or other experimental or approved acute therapy for this stroke event
14. Chest radiograph or clinical presentation suggestive of pneumonia at baseline.
15. Temperature upon admission greater than or equal to 38°C