I wouldn't close for a cold either...I'm having a horrible one right now! My son too. And actually you can't pass colds back and forth, once you've had a cold virus you won't get it again..only a new one. It's a gross time of year for bugs and it sounds like you guys just keep getting different ones. Once it dries up some and warms up, everyone will be feeling much better! In the meantime, double your sanitizing routine!