Scott Jensen admits he was nervous going into this year’s Arrowhead 135 winter race in northeast Minnesota, given all the hoopla about the dreaded polar vortex and forecast record cold temperatures.

That’s understandable when you’re gearing up for a grueling, 135-mile wilderness ride on a fat-tire bike from International Falls to Tower, Minn.

“It was sort of a sense of foreboding,” said Jensen, 57, a Grand Forks, N.D., attorney and fat-tire bike enthusiast. “We woke up Sunday morning up in International Falls, it was 44 below, and my car wouldn’t start.”

Sleep was hard to come by on Sunday night, Jensen says, and his mind was racing in the hours leading up to the race, which got underway at 7 a.m. on Jan. 28, in International Falls. Competitors who didn’t drop out along the way had to cross the finish line at Fortune Bay Casino near Tower by 7 p.m.on Jan. 30.

Riding a Salsa Beargrease fat bike, Jensen finished the race at 8 a.m. on Jan. 29 with a time of 25 hours, 50 minutes, good enough for 25th place. This was his seventh Arrowhead, which is open to competitors on bike, skis and on foot.

A total of 178 participants in the three categories started the race, and 52 finished — 39 bike riders and 13 of the 65 runners who entered.

The temperature was about 10 below zero at the start of the race and warmed up slightly throughout the day, Jensen says. By the time he crossed the finish line in Tower, the mercury had plummeted to nearly 25 below zero with a windchill of 47 below.

Conditions worsened throughout the day.

It’s been cold other years, too, including a low of minus 33 last year, but “this year was definitely cold,” Jensen said.

Aside from breaks at the three checkpoints along the route, Jensen pedaled throughout the night, guided only by the headlight of his bike and the GPS he opted to carry this year after going off-course for about 5 miles during last year’s race.

He took his longest break at the 70-mile checkpoint, MelGeorge’s Elephant Lake Lodge and Resort near Orr, Minn., spending a solid two hours drying off, eating and making sure he wasn’t frostbitten.

Frostbite was especially a concern after a racer last year lost all or parts of six toes, Jensen says.

Jensen dressed in layers, wearing two pairs of bike shorts, three pairs of long wool underwear and light ski pants on his legs. On his upper body, he wore a base layer of thermal underwear, thin wool sweaters, a light jacket and a vest he bought at a gas station on the drive to International Falls.

On his feet, he wore oversize biking boots that clip into the pedals and two pairs of thin wool socks with plastic bags between them. He wore two light polypropylene caps.

Despite the cold, staying dry was an issue throughout the race, Jensen says. By the time he reached the third checkpoint at mile 111, Jensen says so much ice had built up on his sweaters that he couldn’t get them off.

This year, Jensen says he kept his water from freezing like it did last year by carrying the hydration pack inside his coat and vest. In addition, Pat White of the Ski and Bike Shop in Grand Forks mounted a small container for carrying hot liquids on the handlebars of Jensen’s bike.

“I was actually able to drink (hot chocolate) while I biked, just by reaching down, picking that up, popping the lid, and that was fantastic,” Jensen said. “It’s just really nice to be able to drink something warm like that once an hour or so.”

As for next year, the jury’s still out on whether Jensen will race again, but he admits it’s addicting.

“When I got to the finish line, very pointedly I told them I’m going to leave a spot open for somebody else next year, but they reminded me that I say that every year,” Jensen said. “You don’t feel that good by the time you’re done. We’ll see.”