I am a teaching assistant, and I find I cope Ok at work. My kids are aged 4-7, and yes they sometimes do get sick in the classroom. But it isn't my job to clean it up, I will make some excuse like fetching a bucket or getting the caretaker and get out of there! I also find that I am a lot calmer when things like that happen at work than if it was say my neice, I guess professionalism takes over and I have a private freak out later.