Sorry if it was not understood...watch belonged to the student. Student nurse was expected to keep his watch on his arm and not give it to the child.
OK, that does make a lot of sense, especially why that would be a problem with infection control. I read somewhere that watches are third (after pens and stethoscopes) for carrying pathogens between rooms due to the fact that there are very hard to clean and have a lot of places where pathogens can hide.