BARRIE, ONT. -- Simcoe County and Muskoka students are preparing to head back to school on Monday, and now there is more information about what they can expect, but not everyone is satisfied with the Ontario government's plan.

The Ontario Secondary School Teachers' Federation is questioning whether enough is being done.

Local District 17 President Jen Hare said teachers want to be back in the classrooms but are nervous. "Our students take their masks off to eat lunch," said Hare. "In Simcoe County, in the secondary level, we can see class sizes up to 34 students, and in that sort of environment, this virus can spread very rapidly."

The province has added several safety measures, including mandatory three-layer masks, asymptomatic testing and enhanced screening for secondary students and staff.

Students in grades one to three are now required to wear masks, but both the Simcoe County District School Board (SCDSB) and the Simcoe Muskoka Catholic District School Board (SMCDSB) are also requiring it for students in Junior Kindergarten and Kindergarten.

Hare pointed out that schools in York Region will remain closed until Feb. 16, but nearby schools in Bradford have more students and higher numbers of COVID cases.

"In Newmarket, classes are capped at 15, and they're seeing lower numbers of COVID transmission than we see in Bradford. Whereas Bradford can have class sizes up to 36," she said.

But the Simcoe Muskoka District Health Unit has endorsed the province's plan and says now is a safe time to reopen schools.

"We have to look at all of the preventative measures in an additive way, over the course of the day. It's not one piece or another," said Associate Medical Officer of Health Dr. Lisa Simon on Wednesday.

When it comes to the rapid and asymptomatic testing promised by the province, the SMDHU is still learning about the initiative but will be working with local school boards in the coming days to develop a plan.

Dr. Simon revealed that the testing will be mobile. "The Ministry of Education has contracted out mobile vendors who will come to the school to do this asymptomatic testing."

Simon also pointed out that the testing will be targeted and will most likely be used in schools where they believe there could be asymptomatic carriers of COVID-19.

"It's really not very helpful to do this in any random school at any point in time because the chances of finding anyone with COVID is very small, from the experience of doing this asymptomatic testing in other settings," said Simon.

Ontario is also considering cancelling March break in an effort to curb the spread of COVID-19 and hopes to have a decision by next week.

Education Minister Stephen Lecce said he's waiting on the opinion of the province's chief medical officer of health before making a final call.

"I will follow his advice and do whatever it takes to protect Ontario families," he said in a statement. "I believe Canadians should stay home and avoid travel given the emergence of these new variants."

Meanwhile, the unions representing the province's elementary, secondary and Catholic school teachers said mental health should also be considered.

"We are living in unprecedented times that continue to create high levels of stress, fear and anxiety for everyone," said Sam Hammond, president of the Elementary Teachers' Federation of Ontario. "We have heard repeatedly that students, families and educators need a break right now."

He said travel-related concerns should be dealt with in other ways.