426. It was 38 degrees outside. Brad found a seat in the second floor classroom. It was near one of three huge windows. The windows overlooked 36th Street. No icy drafts blew past any window edges. If nothing else, it was a warm room with a view. Brad hoped the three‐hour class would go by fast. The teacher entered the room. He talked for about ten minutes. Then he said, "I feel a little warm. You folks don't mind if I open a window a bit, do you?" One student assented. The teacher opened a window about two inches. Within seconds, Brad felt the chill. He put on his heavy coat and his ski cap. He stopped taking notes. He dug his hands into his coat pockets. When he got home, he told his wife about the freezing classroom. She said, "Why didn't you ask the teacher to close the window?!" 2.5