For the hypothermia procedures, a mixed anesthetic gas (5% isoflurane, 33% O2, 67% N2O) was used for induction for both the ice-pack/warming pad and water immersion methods; 1.5% or 1%Isoflurane, plus 33% O2, 67% N2O were used to maintain a surgical plane of anesthesia for both methods. To achieve reliable results in a pilot study of hypothermic preconditioning in ischemic stroke, a new technique was designed to cool and regulate brain temperatures in mice. The target temperatures in brains were 32 .C, and 28 .C. According to several reports