I watched an interview with Jim Marshal, he explained how the old Met stadium turf had steam pipes that ran down the hash lines to defrost the turf. Bud Grant and the coaches designed their passing plays to use the thawed areas and they designed their defense to keep opponents inside on the frozen turf.
He also talked about the Vikings players on the sidelines without heat, in their short sleeves, gazing at the Odin statue near the scoreboard chanting “Odin, Odin, Odin...”. Really freaked-out their opponents!
Of course, the Purple People Eaters of those days had talent enough to put an opponent pretty much where they wanted them to go. But that’s interesting about the steam pipes. I never knew that.
Those were great days. Teams would come up here in December to play and they’d just wilt.