Teaching and Feeling under the weather don't match

Today I've been feeling a bit under the weather. 'What's the big deal' you would say... Well, it is actually. I'm an ENGLISH TEACHER and one of the main elements of teaching is talking to another person. So, when I lose my voice and cough all the time, things get a bit embarrassing and unprofessional. Well, so what do we, teachers need to do when we are about to catch a cold?