We all know the temperature is crucial in ischemic stroke and will be controlled during ischemia.  Keep in mind that brain temperature may not be the same as the body temperature in your experiment. The ideal way is to monitor the pericranial temperature. However, rectal temperature control is easy, so we all like to use it.

I want to share my opinions here.

1) If you use a heating pad during ischemia, please watch the delayed heating, which may affect your results. The power for the heating pad is shut down when the target temperature is reached. However, the pad still has heating (>40), so the animal's body temperature will continue to increase.  We like to use an adjustable heating pad, where the temperature is set at 35 degrees, then use a heating lamp to bring the body temperature to 37. 

2) If you use a heating lamp, please see where your heating lamp is placed. If you put a heating lamp close to the head, the pericranial temperature may be about 1 degree higher than the body temperature. A high temperature increases brain damage and also has a risk of hemorrhagic transformation in the ischemic brain.