The thermometer will not be poisoned if it is broken, and it can evaporate in the air very quickly. Usually, the concentration in the air will be half in 15 minutes, and after 2 hours, it can basically reach the normal concentration, so it will not cause poisoning. The most important thing is to ventilate the room in time after the thermometer is broken. Theoretically, a broken thermometer can cause poisoning because the amount of mercury in a thermometer is equivalent to the lethal dose of a normal human body. So inhaling all the mercury from a thermometer into the lungs can cause poisoning, but mercury does not cause poisoning through the digestive tract and skin contact. That is why it is important to open a window and ventilate the room when the mercury meter breaks. The mercury in a mercury meter usually evaporates after 2 hours. 6 hours later, it completely evaporates, so it is most important to open a window and ventilate the room to avoid mercury in a confined space. In addition, if the mercury meter is broken on the floor and you see it, you can use some dry paper towels, use a piece of wood or something to rattle onto the piece of paper, and then throw it in the trash can.