New Delhi authorities on November 13 announced a one-week closure of schools and said they would consider a "pollution lockdown" to protect citizens from toxic smog.
"Schools will be shut so that children don't have to breathe polluted air," Delhi's chief minister Arvind Kejriwal told reporters.
Delhi is ranked one of the world's most polluted cities, with a hazardous melange of factory and vehicle emissions, and smoke from agricultural fires, settling in the skies over its 20 million people each winter.
On November 13, the Supreme Court suggested imposing a lockdown on Delhi to combat the air quality crisis.
Kejriwal said his government would consider the court's suggestion after consulting with stakeholders. He said construction activity would be halted for four days to cut down dust from vast, open sites.
Government offices were asked to operate from home and private businesses advised to stick to work-from-home options as much as possible.
The Central Pollution Control Board on November 12 advised authorities to prepare "for implementation of measures under 'emergency' category".
It added the poor air quality would likely run until at least November 18 due to "low winds with calm conditions during the night".
On November 13, levels of PM 2.5 particles – the smallest and most harmful, which can enter the bloodstream – topped 300 on the air quality index.
That is 20 times the maximum daily limit recommended by the World Health Organisation.
Hospitals were reporting a sharp rise in patients complaining of breathing difficulties, the Times of India reported.