There are 10 New South Wales residents younger than 20 in intensive care with Covid-19, sparking a chilling warning to young people.
A staggering 239 new infections were diagnosed overnight, marking the darkest day for the Australian state since the pandemic began.
Fifty-four people were in ICU in NSW, including two teenagers and eight residents in their 20s.
Another four in their 30s and three in their 40s were also in intensive care, debunking a myth that Covid only impacts older people.
NSW chief health officer Kerry Chant said 22 people are on ventilators but did not reveal which age brackets they fit into.
"They're young," she said of the patients in ICU.
"Many of the cases are young. It's not only an old persons' disease. So everyone should discuss vaccination. My message is get vaccinated."
The warning comes after a 38-year-old woman died from Covid last week. Adriana Midori Takara died at Royal Prince Alfred Hospital after she contracted the disease.
The Brazilian citizen, who was studying accounting in Sydney, had no underlying health conditions but died about 10 days after testing positive to the highly contagious Delta variant.
The NSW Premier Gladys Berejiklian on Thursday said at least 66 of the new cases were in the community for their entire infectious period.
The new figures came from more than 110,000 tests in the latest reporting period.
"We can only assume that things are likely to get worse before they get better, given the number of people infectious in the community," Berejiklian said.
"Can we stress again, as we have in the last few weeks, that most of these transmissions are occurring among households and in workplaces, but also in health settings.
"If you're going to a pharmacist or a GP, make sure you don't have symptoms, make sure that you're asking for medical help from home if you need help while you have symptoms."