Despite the implementation of a national action plan and a deployed monitoring of intoxications, Algeria deplores each year more than 2000 victims, who require immediate medical care, and a hundred deaths. For this reason, the risk of carbon monoxide poisoning is not negligible in confined spaces. The gases used or generated by certain work processes or household appliances can impoverish the air. When the oxygen content in the air, is usually 21%, it decreases to less than 15%, which creates a risk of carbon monoxide poisoning. Under-oxygenation leads to the physical and mental capacities' reduction, with the victim's unawareness of it. At 10% of oxygen in the air, the victim faints. Below 10% the victim dies within minutes, unless immediately rescued. Through this research, we are trying to highlight the dangers associated with faulty domestic appliances (heating, water heaters, barbecues, etc.), mainly affecting low class population. This poisoning, preventable and treatable, is a public health issue, which must be treated urgently, mainly during the winter period.