How atropine cause hyperthermia?

Answer 1

Atropine antagonises central muscarinic receptors (remember, the parasympathetic nervous system is made up of muscarinic and nicotinic receptors). This muscarinic receptor antagonising alters temperature regulation in the hypothalamus -- the mechanism how it works is unfortunately not understood. But is is known that it reduces blood flow to the skin, thus reducing the ability for the body to lose heat and increasing body temperature. Similar to Adrenaline (Epinephrine for you North American types) I take it, although a brief search could not link adrenaline to hyperthermia (if you know of anything, please let me know).

Answer 2

Atropine can cause hyperthermia by blocking the action of acetylcholine in the body, leading to decreased sweating and reduced heat dissipation. This disruption in the body's normal temperature regulation mechanisms can result in an increase in body temperature and the development of hyperthermia.