what are nosebleed seats

Nosebleed seats are the seats in a public area, usually an athletic stadium or gymnasium, that are highest and farthest from the desired activity. They are usually located at the top rows of the bleachers and are so high and far away from the stage or field that you get a "nosebleed" from the high altitude. The term "nosebleed section" is a tongue-in-cheek reference to the tendency for mountain climbers to suffer nosebleeds at high altitudes. The term appeared in print as early as 1953 when it was used to describe the last row in the end zone at Philadelphias Municipal Stadium during that year's Army-Navy American football game.