Electric heaters can be used in closed rooms. Electric heaters usually use electricity as heating energy, which will not produce toxic gas or consume indoor oxygen, so they can be used in closed rooms.
Precautions:
However, it is best to choose an electric heater without an open flame and with an overheating device, because in a closed room in winter, an open flame will not only consume indoor oxygen, pollute the environment, but also cause accidents such as burns and fires if you are not careful. Also pay attention to the safety of electricity use.
Many vehicles have a switch at the connection between the heating water pipe and the engine. Turn on this switch in winter, otherwise the engine water will not circulate to the warm air box, and there is no warm air.