Every year in winter, dozens of patients with gas poisoning are admitted to the hyperbaric chamber of our hospital. The main component of gas is “carbon monoxide”. Because carbon monoxide is colorless and tasteless, people are weak after poisoning, and sometimes even if they are still conscious, they are still unable to save themselves, so it is called an “invisible killer”. Carbon monoxide poisoning is mostly seen in improper use of gas, car exhaust poisoning, etc. Some people say that the natural gas we use seems to be non-toxic. Pure natural gas is almost non-toxic, but this is not the same as being harmless to the human body. There are two kinds of natural gas poisoning: 1. In winter, the doors and windows are generally closed, and there is not enough indoor air circulation, so if a natural gas leak occurs, it is bound to reduce the air composition in the house, and thus a lack of oxygen occurs, and the longer the lack of oxygen, the more serious the consequences, until a life-threatening situation occurs. 2, natural gas combustion requires the consumption of indoor oxygen, a longer period of time after using the water heater, coupled with poor indoor ventilation (often closed doors and windows in winter, poor ventilation), indoor oxygen is consumed in large quantities, in addition to indoor oxygen deficiency, will cause the combustion of natural gas in the absence of oxygen, resulting in a large amount of carbon monoxide, resulting in acute carbon monoxide poisoning. There is also a more special situation where the exhaust gas from natural gas combustion is discharged indoors and then blown back into the room by the return wind to produce poisoning. In addition to natural gas, liquefied gas poisoning is caused by the same reasons as natural gas. Higher concentrations of liquefied gas also have a narcotic effect on the human body. In addition to these two gases, some people use charcoal pots for heating in winter, and in the case of poor ventilation, incomplete combustion of coal (charcoal), etc. produces a large amount of carbon monoxide, which can unknowingly produce extremely serious consequences. Therefore, the use of gas water heaters in winter remember to ventilate, water heaters to ask professionals to install correctly, try to avoid the use of gas water heaters for a long time. Gas switches, valves, pipes, connecting pipes, etc. should be regularly inspected and maintained. Winter hot pot (using gas) should also pay attention to ventilation, so as not to eat gas poisoning to. The use of briquette stoves, charcoal pots should pay more attention to ventilation.