Now that I work as a fulltime teacher where my working schedule amounts to six to seven hours of work for lecture and laboratory, I am quite drained physically to top everything.
Teaching in a full class of 40 - 50 students, having a modulated voice is only necessary. So, when teacher is sick, teaching can be quite a toil and disrupting too for students. If possible, sick students and teachers are advised to do bed rest and take needed medicines like generic lipitor tablets if their physicians would warrant them. We don't want to infect others at school especially if our illnesses are contagious.
Before we get sick, it would be smarter to take some vitamins for extra immunity boost, exercise regularly and have better sleep schedules and diet.