Teachers don't have time to get sick during term time, there is too much to do. You can't miss a class because... they are just about to have an assessment, they are going on an excursion, it is an important part of the topic... You can't miss a day because.... you have organised a meeting with a parent, you are helping a student at lunchtime, you have reports to write...
It is easy for the stress to build up during the term and not to have time for yourself to wind-down. Teachers wait until the holidays to relax and wind-down, it is then they have time to get sick, when there are no classes to teach, to one to let down.
My challenge this term is to schedule time to relax, so I maintain my balance and welfare. I don't want to fall in the teacher's trap next holidays.