What do you do if a student is having a mental health crisis in your classroom? Uncontrollable anxiety? A panic attack? A manic episode? If you are the homeroom teacher, you will deal with it in a very different way than as a substitute teacher.
If you are a homeroom teacher, you want to speak with the student privately and find out what is going on. If it seems they are in deep distress, as soon as possible, ask if they have considered suicide. If they do have a plan and the means to carry it out, call 9-1-1 and get them help. I know this may seem a bit extreme however, this is what is being recommended by Health Canada in their Mental Health First Aid workshops for teachers (I highly recommend taking the course!). It is a myth that asking about suicide will plant the idea in a student’s mind. If they do not have a plan, ask the student what they need. If they do not know, get help from the principal, their parents or a school social worker or counsellor.
If you are a substitute teacher, call the office for help. If you are able to talk with the student while waiting for help, ask them what is going on and how you can help. Again, if the student seems to be in deep distress, do not wait for the office, ask if the student has considered suicide. Again, if they have a plan and the means to carry it out, call 9-1-1. The most important thing is that the student is safe. This is mental health first aid, not counselling. When dealing with a crisis, the most important thing is that the student is safe and that you are getting them help.