Medfield High School will hold separate orientation sessions for parents of eighth-graders and parents of current students on Feb. 27 in the school’s auditorium. At 6:45 p.m., parents of next fall’s freshmen will hear a presentation by administrators and guidance counselors, to be followed by tours of the building led by members of the senior class, and a reception in the school foyer.  At 7:30 p.m., a program for parents of students in grades 9 through 11 will outline what they can expect in the coming school year.