How does carbon monoxide primarily poison the human body?

Carbon monoxide primarily poisons the human body by displacing oxygen in the bloodstream. When inhaled, carbon monoxide binds with hemoglobin in red blood cells much more effectively than oxygen does, forming carboxyhemoglobin. This prevents hemoglobin from transporting oxygen throughout the body, leading to a state of oxygen deprivation, or hypoxia, in vital organs and tissues. As a result, cellular respiration is disrupted, which can lead to serious health consequences, including neurological impairment and death if exposure is prolonged or severe.

The other options do not accurately reflect the biochemical mechanisms of carbon monoxide poisoning. For example, cooling the body is not a direct effect of carbon monoxide; rather, the primary concern is the obstruction of normal oxygen delivery. Enhancing oxygen delivery contradicts the effects of carbon monoxide, while allergic reactions are irrelevant in the context of carbon monoxide exposure. Understanding the mechanism of carbon monoxide's impact emphasizes the importance of proper ventilation and safety measures around sources of combustion.