system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can fire close wounds, and how does fire/heat disinfect?
gpt
Cauterization is not like it is in movies or TV. Yes, heating an *instrument* can sterilize it by physically destroying infectious pathogens from intense heat.

In the body, the intense heat can stop bleeding by physically burning the tissue and clotting the blood. This causes *extensive* tissue damage.

When done by a surgeon, it can effectively be directed to where its needed to stop bleeding. However, this is generally better achieved by ligating (tying off) the bleeding vessel, repairing the tear or using other materials to slow/stop bleeding (such as injecting little gelatin particles into an artery to block if off). In modern medicine, cauterization is actually used to make tiny electric scalpels designed to cut tissue (and also creates the aroma of burning human flesh filling the operating room).

Burns to tissue like shown on TV and movies are actually more likely to get infected due to disruption of skin and tissue which weakens the body's ability to fight infection. People with serious burns need a lot of specialized attention to prevent this, such as in a burn unit.

EDIT: Also in TV you will see people cauterizing arteries that can't be cauterized without cutting off critical blood supply to certain areas of the body. It's not realistic.