Should the child return home immediately if he or she falls ill while traveling?

Yes. If a child falls sick while traveling, he or she should return immediately; if a child develops fever, cough or other symptoms during the trip, he or she should actively wear a mask, seek medical treatment as soon as possible, and terminate the return plan. "Travel" means traveling, going out, that is, the process of traveling from point A to point B in space in order to achieve a certain purpose; "you" means going out for sightseeing, sightseeing, and entertainment, that is, traveling to achieve these purposes.