Gaseous exchange and electrical activity of skeletal muscle were studied in white rats at rest. The rectal temperature varied between 38.5°–40° and 18–11°. It was shown that when the body temperature was high, gaseous exchange was minimal and there was no electrical activity in the muscles. When the body temperature fell, both gaseous exchange and muscular electrical activity first rose and then fell. At very low body temperatures, only the muscles of the proximal parts of the body continued to manifest some electrical activity.