Hotel wake-up calls in 1967 came with the time and temperature. Dallas Cowboys fullback Don Perkins roomed with future Pro Football Hall of Fame defensive back Mel Renfro. After the operator hung up, Renfro stood speechless for a moment with the phone in his hand, staring at his roommate. “The woman said 18 below zero. She must’ve meant above, right?” Perkins and Renfro then walked to the window to have a look outside. Except for they couldn’t. The window was covered in frost, more like a block of ice. When quarterback “Dandy” Don Meredith was informed of the temperature he…