What are the precautions for lighting candles indoors?

If you light candles indoors, it will smell of smoke. Pay attention to the air quality. Candles themselves consume air.

Some of them are rich in oxygen and emit a lot of carbon dioxide. If the oxygen content is lower than our requirements,

If people engage in strenuous activities in this environment for a long time, they will be dizzy, and in serious cases.

It'll hurt your brain.