It is now mandatory for Windsor Regional Hospital nurses to wear masks if they have not received the flu shot.
It's one of several measures put in place in an attempt to stop the spread of the H1N1 flu.
Nurses who are not vaccinated will not have to wear masks during the entire flu season, just when numbers are high and cases are peaking. That's currently the case.
Monday, the Windsor-Essex health unit confirmed 122 cases of influenza. That's twice as many as reported last season.
Windsor Regional Hospital is now one of 10 Ontario hospitals mandating nurses wear masks.
"It's in the interest of the patient," Windsor Regional Hospital CEO David Musyj said. "We're here for the patient so let's focus on the patient and let's make sure the last thing we want to do is harm a patient.
"You can be passing influenza to others even though you're feeling fine."
The Ontario Nurses Association said the regulation is a violation of the nurses' personal rights.
When it was announced that all nurses who aren't vaccinated would have to wear masks, some nurses did complained.
They say it's a stigma to wear a mask and they frighten some patients.
Musyj said masks have a "very minimal impact on the staff member."
So, the two sides worked out the agreement that will see nurses wear masks while flu numbers spike and not the entire flu season, which runs September through March.