The head intensive care nurse at the Royal Melbourne Hospital, Michelle Spence, has said that hospitals are now preparing for the prospect of deaths among younger people.

"What we are seeing now is young people who are going to die. There is no doubt about it," she said.

"And these are people who are 30s, 40s, 50s, who have no past history."

She said that despite deaths in Victoria predominately being older people this is going to change.

Authorities revealed yesterday that 20 per cent of people in Victorian hospitals with the virus were under the age of 50, with four children included in that number. 

Ms Spence said the hospital had patients ranging from their 30s to their 80s "and all of them are at varying degrees of their COVID journey".

"We're definitely not just seeing the elderly, that is not the case at all."

"It is definitely not an old person's disease," Ms Spence said.

Being a patient with COVID-19 in the intensive care unit is no picnic, with very ill people being separated from the families and the process being long and slow.

"Being in ICU is not a nice place to be," she said.

"It is absolutely not a comfortable thing to do."

Her warning comes after Victoria's Premier Daniel Andrews issued a firm warning to younger people.

"It would be wrong to assume that young people are somehow more immune to this," he said.

"If you want this to be over, if you want to get to the other side of it and find that COVID normal … and be able to go and have a beer, or go and have a meal with a friend and be able to move around the community much more freely than you can now, you've got to follow the rules."

Mr Andrews warned: "There are a lot of young people who have died of this in other parts of the world."

"There are a lot of otherwise healthy people … and they have become ill," he said.

"This is not just something that affects people that are frail-aged."

Health Minister Jenny Mikakos agreed, saying it's "not an older person's disease".

"Our data from the start of July shows us that a quarter of the infections that we are seeing in our community are actually amongst young people in their 20s.

"By way of comparison, people in their 60s only represent 6 per cent of people who have been diagnosed with this virus."