If you are sick, stay home or go home.
You have to decide if you are sick.
You don't have to be a martyr but you should only go/stay home if you are really sick.
Cooperating teachers are happy to give you release time if it means that you are interviewing for a job or going for some professional development.
We resent it when you ask for release time for things that could or should be done outside the work day. It puts us in an awkward position.