DETROIT LAKES — Despite single-digit temperatures that continued for much of the weekend, Detroit Lakes was a hive of activity on Saturday, Feb. 15, with several events taking place as part of Polar Fest's middle weekend. At Detroit Mountain Recreation Area, two solo competitors and three teams braved the super-chilled morning temperatures to take on the Sweaty Yeti race, which started at 9 a.m. Solo competitor Ben Olson was the first to cross t…