Editing Carbon monoxide (section)

=== Prehistory ===
Humans have maintained a complex relationship with carbon monoxide since first learning to control fire circa 800,000 BC. Early humans probably discovered the toxicity of carbon monoxide poisoning upon introducing fire into their dwellings. The early development of [[metallurgy]] and [[smelting]] technologies emerging circa 6,000 BC through the [[Bronze Age]] likewise plagued humankind from carbon monoxide exposure. Apart from the toxicity of carbon monoxide, indigenous [[Native Americans in the United States|Native Americans]] may have experienced the neuroactive properties of carbon monoxide through [[shamanistic]] fireside rituals.<ref name="Hopper2021" />