Here is the government link that all guests, staff & students will be required to follow.
In the specific settings where a mask is required, anyone unable to wear a mask due to an approved medical condition will require a medical exception letter from an authorized health professional.
The medical exception letter must come from a nurse practitioner, physician or psychologist.
The medical exception letter may be presented when in a public setting if requested by enforcement officials, or retrospectively in court if a ticket is issued.