How Anesthesia Lowers Your Body Temperature General anesthesia disables the body’s normal heat-preserving defenses, which is why active warming is routine in the OR. ❄️ Anesthesia shuts down shivering and heat regulation Under normal conditions, the hypothalamus triggers vasoconstriction and shivering to maintain core temperature. Anesthetic drugs blunt these responses and reduce metabolic heat production by 20–30 percent, so the body cannot generate warmth on its own. PMID: 28349090 🔄 Heat red