I did a 32 mile "half" adventure race in Wisconsin some years ago, The Frozen Otter. The half race was 32 miles, you had 12 hours to complete it, otherwise you were listed as a DNF. The full race was 64 miles 24 hours. It's held around January 15th every year in North Kettle Moraine State Forest on the Ice Age Trail. That's the historically coldest time of the year for that area. It was relatively new when I did it, it became so popular they no longer do the half race due to so many participants. Before you poo poo Wisconsin terrain, the trail is 32 miles of PUD's,
pointless
ups and
downs. It's a real grind.
There was between 5-8 inches of snow on the ground, start temp was in the teens at the start, single digits at the end. They had check in stations every so many miles so they could track everyone and make sure there were no shenanigans. There were ems staged all throughout the route with snowmobiles. Most of the trail had intersections with or was close to fire roads.
We had very basic minimalist survival gear but nothing that would have kept me from dying from exposure if I went down and couldn't keep moving. Exposure will make you delusional or stupid, then you die. At the end of the race it was 5 degrees, I was only wearing soft shell pants with a lightweight baselayer underneath, a long sleeve merino wool shirt and my GoreTex light mountaineering shell. At the finish line we were all steaming clouds off of our bodies like you see cattle or horses do in very cold temps.
That was the one and only time I did something like that, it took me a week to recover. Probably burned a weeks worth of calories in one 12 hour period.
A friend of mine from work went on to win the 64 mile race one year. Conditions were a little bit better but man, that's just brutal. He was an actual ultramarathon runner, not a poser like me and my buddy who talked me into doing it
If you are remotely interested in ultramarathons I suggest "Born to Run" as a great book to read. Actually even if you aren't a runner it's a great read.
