Couple games come to mind...
2008 7A Semis - Geneva - CL South (it was the only Friday night semifinal game in the state)
15 degrees, a weird back and forth game. Oddly enough, no wind. It was the most comfortable super cold game I can remember seeing. The bars in town after the Vikings clinched their first trip downstate in 33 years were pretty warm though!
2012 7A/8A Final - This was the hardest hitting game I can remember seeing between LWE/GBW (10-8) and the nightcap had MC going for another one. I did sidelines with Susannah Collins. 22 degrees, but the wind was just horrific and it was a 7 degree wind chill. Susannah just gave up and midway through the 8A game just had enough and hid in the bowels of Memorial Stadium. I remember refusing to put on a hat all day just because. Network talent, I tell ya!
2013 4A Final - I remember that Rochester-Geneseo game. I was sidelines for CSN for that one too. 4 layers under the shirt, tie and overcoat and snow pants. I kept moving, but it was a blah game and that's tough after a long day down there.
2015 Semis - The Blizzard - I started the day at Montini and PR in hopes of scouting for the title game I was doing on CSN the next week in 6A. Useless, could not see the other sideline. Weird game. That was supposed to be "the year" for PR. Imagine those seniors and what's happened since. Have to feel bad for those kids (now 20 something)
Night cap I drove to the Southside to do sidelines at Marist. There was nowhere to put the snow when they cleared the field. You worried about the back of the endzone all night. Waubonsie kids were ready to go home after 5 mins. The wind and cold as mentioned for those night games were brutal. I had been there just two weeks earlier and the fans were just ready to leave. All of them! One of the strangest environments I've been in.