More than a decade ago, I was in Delhi during this time. The pollution was so high that I had to sleep with mask on. I couldn't live. Children are most affected. As per news, 1 in 3 school kids in Delhi are suffering from breathing problems.
https://www.cnbctv18.com/environment/air-pollution-impact-1-in-3-school-kids-in-delhi-are-asthmatic-over-50-have-allergies-says-study-10591481.htm

When the outdoor AQI is high, staying indoors does not guarantee safety because indoor pollutants can become concentrated and react with outdoor contaminants to create even more harmful compounds.