If someone calls in sick, Manage. That's your job. It's not to sit at the desk and when someone ask you how it's going you say “I'm Managing”
You find coverage. That's your job. Offer an incentive to someone who isn't sick. If you don't have anyone, or anything to offer, that's either your failing, or that of your boss above you.
Gripes go up, not down. If you're a manager, have an employee call out sick, and send your gripes down at the sick worker, instead of up to your boss (or at yourself if that's where the buck stops) you're a bad manager.
Quit before you are food.