Toxic concentrations in New Delhi's air have reached levels 42 times above what is considered safe, reigniting questions about how the rapidly-developing city can tackle its persistent air pollution crisis.
Yesterday, New Delhi's Chief Minister Arvind Kejriwal branded the city a "gas chamber" as the thick haze left eyes watering and throats burning.
US embassy monitoring equipment recorded the concentration of PM2.5 — the smallest, most harmful particles — at 762 about midday on Tuesday (local time).
The figure is quite literally off the scale — well above the 300 to 500 levels that the US Environmental Protection Agency considers hazardous and a respiratory risk to the general population.
Indian Medical Authority's President Dr Krishnan Kumar Aggarwal declared Delhi "a public health emergency state".
"Schools should be closed down, people should not step out of their homes, especially the elderly, pregnant ladies, children, heart and asthma patients," he said.
Another doctor, Dr Arvind Kumar, compared the air to smoking 50 cigarettes a day.
"We need to bring these levels down. We are all shortening our lives," the chairman for chest surgery at Sir Ganga Ram hospital said.
"It's very difficult to breathe and it's causing a lot of skin problems," Aanchal Chauhan, an 18-year-old university student told the ABC.
The toxic cloud smothering northern India comprises dust, emissions and crop smoke, unable to disperse in the cooling, condensing autumn air.
It is, sadly, an annual phenomenon, one that this group of students says is still shrugged off by Governments and citizens.
"No, they're not concerned about it," said another student, Sarjana Maini.
"People are not concerned about environment issues."
Globally, India records the most early deaths due to pollution — 2.5 million, followed by China with 1.8 million, according to a Lancet Commission on Pollution and Health study, released last month.
Asked if she worried, Ms Maini said, "Yeah of course I worry, this [New Delhi] is not a healthy place to be".
Last night, Delhi's Government ordered primary schools closed today and banned older children from playing outside.
It also announced plans to water roads and construction sites to combat dust, shut brick kilns, and hike parking fees to discourage driving.
Those measures might not be necessary critics say, had the Government done more to honour promises like stopping illegal stubble burning and improving public transport.